diff --git a/.cirrus.yml b/.cirrus.yml
index 15be5de..ade4ba2 100644
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+#
+# SPDX-License-Identifier: CC0-1.0
+
 container:
   image: golang:latest
 
diff --git a/.github/FUNDING.yml b/.github/FUNDING.yml
index 2db91cf..e1400c1 100644
--- a/.github/FUNDING.yml
+++ b/.github/FUNDING.yml
@@ -1,2 +1,6 @@
+# SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+#
+# SPDX-License-Identifier: CC0-1.0
+
 github: wneessen
 ko_fi: winni
diff --git a/.github/ISSUE_TEMPLATE/bug_report.yml b/.github/ISSUE_TEMPLATE/bug_report.yml
index 3fd5e1d..aa1cd05 100644
--- a/.github/ISSUE_TEMPLATE/bug_report.yml
+++ b/.github/ISSUE_TEMPLATE/bug_report.yml
@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+#
+# SPDX-License-Identifier: CC0-1.0
+
 name: Bug Report
 description: Create a report to help us improve
 # title: ""
diff --git a/.github/ISSUE_TEMPLATE/config.yml b/.github/ISSUE_TEMPLATE/config.yml
index e52a896..f6ea6d2 100644
--- a/.github/ISSUE_TEMPLATE/config.yml
+++ b/.github/ISSUE_TEMPLATE/config.yml
@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+#
+# SPDX-License-Identifier: CC0-1.0
+
 blank_issues_enabled: false
 contact_links:
   - name: GitHub Community Discussions
diff --git a/.github/ISSUE_TEMPLATE/feature_request.yml b/.github/ISSUE_TEMPLATE/feature_request.yml
index d29e823..d2dae5e 100644
--- a/.github/ISSUE_TEMPLATE/feature_request.yml
+++ b/.github/ISSUE_TEMPLATE/feature_request.yml
@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+#
+# SPDX-License-Identifier: CC0-1.0
+
 name: Feature request
 description: Suggest an idea for this project
 # title: ""
diff --git a/.github/workflows/codecov.yml b/.github/workflows/codecov.yml
index 35768f3..b146ef2 100644
--- a/.github/workflows/codecov.yml
+++ b/.github/workflows/codecov.yml
@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+#
+# SPDX-License-Identifier: CC0-1.0
+
 name: Codecov workflow
 on:
   push:
diff --git a/.github/workflows/codeql-analysis.yml b/.github/workflows/codeql-analysis.yml
index 14cab03..b9c06c1 100644
--- a/.github/workflows/codeql-analysis.yml
+++ b/.github/workflows/codeql-analysis.yml
@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+#
+# SPDX-License-Identifier: CC0-1.0
+
 # For most projects, this workflow file will not need changing; you simply need
 # to commit it to your repository.
 #
diff --git a/.github/workflows/sonarqube.yml b/.github/workflows/sonarqube.yml
index e6d8f21..a604239 100644
--- a/.github/workflows/sonarqube.yml
+++ b/.github/workflows/sonarqube.yml
@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+#
+# SPDX-License-Identifier: CC0-1.0
+
 name: SonarQube
 on:
   push:
diff --git a/.gitignore b/.gitignore
index 305a3eb..1a4a15d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+#
+# SPDX-License-Identifier: CC0-1.0
+
 # Binaries for programs and plugins
 *.exe
 *.exe~
@@ -16,7 +20,10 @@
 
 # Local testfiles and auth data
 .auth
-cmd/main.go
+cmd/*
 
 # SonarQube
-.scannerwork/
\ No newline at end of file
+.scannerwork/
+
+# IDEA
+.idea/workspace.xml
diff --git a/.idea/go-mail.iml.license b/.idea/go-mail.iml.license
new file mode 100644
index 0000000..f9b629a
--- /dev/null
+++ b/.idea/go-mail.iml.license
@@ -0,0 +1,3 @@
+SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+
+SPDX-License-Identifier: CC0-1.0
diff --git a/.idea/inspectionProfiles/Project_Default.xml b/.idea/inspectionProfiles/Project_Default.xml
index 09dbac8..06bcfde 100644
--- a/.idea/inspectionProfiles/Project_Default.xml
+++ b/.idea/inspectionProfiles/Project_Default.xml
@@ -1,3 +1,9 @@
+<!--
+SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+
+SPDX-License-Identifier: CC0-1.0
+-->
+
 <component name="InspectionProjectProfileManager">
   <profile version="1.0">
     <option name="myName" value="Project Default" />
diff --git a/.idea/markdown.xml b/.idea/markdown.xml
new file mode 100644
index 0000000..8f0a1a0
--- /dev/null
+++ b/.idea/markdown.xml
@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<!--
+SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+
+SPDX-License-Identifier: CC0-1.0
+-->
+
+<project version="4">
+  <component name="MarkdownSettings">
+    <enabledExtensions>
+      <entry key="MermaidLanguageExtension" value="false" />
+      <entry key="PlantUMLLanguageExtension" value="false" />
+    </enabledExtensions>
+  </component>
+</project>
\ No newline at end of file
diff --git a/.idea/modules.xml b/.idea/modules.xml
index e4c35b6..c0cf64a 100644
--- a/.idea/modules.xml
+++ b/.idea/modules.xml
@@ -1,4 +1,11 @@
 <?xml version="1.0" encoding="UTF-8"?>
+
+<!--
+SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+
+SPDX-License-Identifier: CC0-1.0
+-->
+
 <project version="4">
   <component name="ProjectModuleManager">
     <modules>
diff --git a/.idea/vcs.xml b/.idea/vcs.xml
index 94a25f7..cf5b8e0 100644
--- a/.idea/vcs.xml
+++ b/.idea/vcs.xml
@@ -1,4 +1,11 @@
 <?xml version="1.0" encoding="UTF-8"?>
+
+<!--
+SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+
+SPDX-License-Identifier: CC0-1.0
+-->
+
 <project version="4">
   <component name="VcsDirectoryMappings">
     <mapping directory="$PROJECT_DIR$" vcs="Git" />
diff --git a/.reuse/dep5 b/.reuse/dep5
new file mode 100644
index 0000000..70261ce
--- /dev/null
+++ b/.reuse/dep5
@@ -0,0 +1,10 @@
+Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
+Upstream-Name: go-mail
+Upstream-Contact: Winni Neessen <winni@neessen.dev>
+Source: https://github.com/wneessen/go-mail
+
+# Sample paragraph, commented out:
+#
+# Files: src/*
+# Copyright: $YEAR $NAME <$CONTACT>
+# License: ...
diff --git a/CODE_OF_CONDUCT.md b/CODE_OF_CONDUCT.md
index d700821..be485b6 100644
--- a/CODE_OF_CONDUCT.md
+++ b/CODE_OF_CONDUCT.md
@@ -1,3 +1,9 @@
+<!--
+SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+
+SPDX-License-Identifier: CC0-1.0
+-->
+
 # Contributor Covenant Code of Conduct
 
 ## Our Pledge
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 39b0974..1611a3a 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -1,3 +1,9 @@
+<!--
+SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+
+SPDX-License-Identifier: CC0-1.0
+-->
+
 # How to contribute
 
 **Working on your first Pull Request?** You can learn how from this *free* series [How to Contribute to an Open Source Project on GitHub](https://egghead.io/courses/how-to-contribute-to-an-open-source-project-on-github)
diff --git a/LICENSES/CC0-1.0.txt b/LICENSES/CC0-1.0.txt
new file mode 100644
index 0000000..0e259d4
--- /dev/null
+++ b/LICENSES/CC0-1.0.txt
@@ -0,0 +1,121 @@
+Creative Commons Legal Code
+
+CC0 1.0 Universal
+
+    CREATIVE COMMONS CORPORATION IS NOT A LAW FIRM AND DOES NOT PROVIDE
+    LEGAL SERVICES. DISTRIBUTION OF THIS DOCUMENT DOES NOT CREATE AN
+    ATTORNEY-CLIENT RELATIONSHIP. CREATIVE COMMONS PROVIDES THIS
+    INFORMATION ON AN "AS-IS" BASIS. CREATIVE COMMONS MAKES NO WARRANTIES
+    REGARDING THE USE OF THIS DOCUMENT OR THE INFORMATION OR WORKS
+    PROVIDED HEREUNDER, AND DISCLAIMS LIABILITY FOR DAMAGES RESULTING FROM
+    THE USE OF THIS DOCUMENT OR THE INFORMATION OR WORKS PROVIDED
+    HEREUNDER.
+
+Statement of Purpose
+
+The laws of most jurisdictions throughout the world automatically confer
+exclusive Copyright and Related Rights (defined below) upon the creator
+and subsequent owner(s) (each and all, an "owner") of an original work of
+authorship and/or a database (each, a "Work").
+
+Certain owners wish to permanently relinquish those rights to a Work for
+the purpose of contributing to a commons of creative, cultural and
+scientific works ("Commons") that the public can reliably and without fear
+of later claims of infringement build upon, modify, incorporate in other
+works, reuse and redistribute as freely as possible in any form whatsoever
+and for any purposes, including without limitation commercial purposes.
+These owners may contribute to the Commons to promote the ideal of a free
+culture and the further production of creative, cultural and scientific
+works, or to gain reputation or greater distribution for their Work in
+part through the use and efforts of others.
+
+For these and/or other purposes and motivations, and without any
+expectation of additional consideration or compensation, the person
+associating CC0 with a Work (the "Affirmer"), to the extent that he or she
+is an owner of Copyright and Related Rights in the Work, voluntarily
+elects to apply CC0 to the Work and publicly distribute the Work under its
+terms, with knowledge of his or her Copyright and Related Rights in the
+Work and the meaning and intended legal effect of CC0 on those rights.
+
+1. Copyright and Related Rights. A Work made available under CC0 may be
+protected by copyright and related or neighboring rights ("Copyright and
+Related Rights"). Copyright and Related Rights include, but are not
+limited to, the following:
+
+  i. the right to reproduce, adapt, distribute, perform, display,
+     communicate, and translate a Work;
+ ii. moral rights retained by the original author(s) and/or performer(s);
+iii. publicity and privacy rights pertaining to a person's image or
+     likeness depicted in a Work;
+ iv. rights protecting against unfair competition in regards to a Work,
+     subject to the limitations in paragraph 4(a), below;
+  v. rights protecting the extraction, dissemination, use and reuse of data
+     in a Work;
+ vi. database rights (such as those arising under Directive 96/9/EC of the
+     European Parliament and of the Council of 11 March 1996 on the legal
+     protection of databases, and under any national implementation
+     thereof, including any amended or successor version of such
+     directive); and
+vii. other similar, equivalent or corresponding rights throughout the
+     world based on applicable law or treaty, and any national
+     implementations thereof.
+
+2. Waiver. To the greatest extent permitted by, but not in contravention
+of, applicable law, Affirmer hereby overtly, fully, permanently,
+irrevocably and unconditionally waives, abandons, and surrenders all of
+Affirmer's Copyright and Related Rights and associated claims and causes
+of action, whether now known or unknown (including existing as well as
+future claims and causes of action), in the Work (i) in all territories
+worldwide, (ii) for the maximum duration provided by applicable law or
+treaty (including future time extensions), (iii) in any current or future
+medium and for any number of copies, and (iv) for any purpose whatsoever,
+including without limitation commercial, advertising or promotional
+purposes (the "Waiver"). Affirmer makes the Waiver for the benefit of each
+member of the public at large and to the detriment of Affirmer's heirs and
+successors, fully intending that such Waiver shall not be subject to
+revocation, rescission, cancellation, termination, or any other legal or
+equitable action to disrupt the quiet enjoyment of the Work by the public
+as contemplated by Affirmer's express Statement of Purpose.
+
+3. Public License Fallback. Should any part of the Waiver for any reason
+be judged legally invalid or ineffective under applicable law, then the
+Waiver shall be preserved to the maximum extent permitted taking into
+account Affirmer's express Statement of Purpose. In addition, to the
+extent the Waiver is so judged Affirmer hereby grants to each affected
+person a royalty-free, non transferable, non sublicensable, non exclusive,
+irrevocable and unconditional license to exercise Affirmer's Copyright and
+Related Rights in the Work (i) in all territories worldwide, (ii) for the
+maximum duration provided by applicable law or treaty (including future
+time extensions), (iii) in any current or future medium and for any number
+of copies, and (iv) for any purpose whatsoever, including without
+limitation commercial, advertising or promotional purposes (the
+"License"). The License shall be deemed effective as of the date CC0 was
+applied by Affirmer to the Work. Should any part of the License for any
+reason be judged legally invalid or ineffective under applicable law, such
+partial invalidity or ineffectiveness shall not invalidate the remainder
+of the License, and in such case Affirmer hereby affirms that he or she
+will not (i) exercise any of his or her remaining Copyright and Related
+Rights in the Work or (ii) assert any associated claims and causes of
+action with respect to the Work, in either case contrary to Affirmer's
+express Statement of Purpose.
+
+4. Limitations and Disclaimers.
+
+ a. No trademark or patent rights held by Affirmer are waived, abandoned,
+    surrendered, licensed or otherwise affected by this document.
+ b. Affirmer offers the Work as-is and makes no representations or
+    warranties of any kind concerning the Work, express, implied,
+    statutory or otherwise, including without limitation warranties of
+    title, merchantability, fitness for a particular purpose, non
+    infringement, or the absence of latent or other defects, accuracy, or
+    the present or absence of errors, whether or not discoverable, all to
+    the greatest extent permissible under applicable law.
+ c. Affirmer disclaims responsibility for clearing rights of other persons
+    that may apply to the Work or any use thereof, including without
+    limitation any person's Copyright and Related Rights in the Work.
+    Further, Affirmer disclaims responsibility for obtaining any necessary
+    consents, permissions or other rights required for any use of the
+    Work.
+ d. Affirmer understands and acknowledges that Creative Commons is not a
+    party to this document and has no duty or obligation with respect to
+    this CC0 or use of the Work.
diff --git a/LICENSES/MIT.txt b/LICENSES/MIT.txt
new file mode 100644
index 0000000..2071b23
--- /dev/null
+++ b/LICENSES/MIT.txt
@@ -0,0 +1,9 @@
+MIT License
+
+Copyright (c) <year> <copyright holders>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
diff --git a/README.md b/README.md
index d7718ba..289ee02 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,9 @@
+<!--
+SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+
+SPDX-License-Identifier: CC0-1.0
+-->
+
 # go-mail - Simple and easy way to send mails in Go
 
 [![GoDoc](https://godoc.org/github.com/wneessen/go-mail?status.svg)](https://pkg.go.dev/github.com/wneessen/go-mail)
diff --git a/SECURITY.md b/SECURITY.md
index 78909df..eb08a78 100644
--- a/SECURITY.md
+++ b/SECURITY.md
@@ -1,3 +1,9 @@
+<!--
+SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+
+SPDX-License-Identifier: CC0-1.0
+-->
+
 # Security Policy
 
 ## Reporting a Vulnerability
diff --git a/auth.go b/auth.go
index 33f4ed4..51abdb9 100644
--- a/auth.go
+++ b/auth.go
@@ -1,3 +1,7 @@
+// SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+//
+// SPDX-License-Identifier: MIT
+
 package mail
 
 import "errors"
diff --git a/auth/auth_test.go b/auth/auth_test.go
index 336ed64..e1a57b2 100644
--- a/auth/auth_test.go
+++ b/auth/auth_test.go
@@ -1,3 +1,7 @@
+// SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+//
+// SPDX-License-Identifier: MIT
+
 package auth
 
 import (
diff --git a/auth/login.go b/auth/login.go
index 64e2ecc..50cbc4f 100644
--- a/auth/login.go
+++ b/auth/login.go
@@ -1,3 +1,7 @@
+// SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+//
+// SPDX-License-Identifier: MIT
+
 // Package auth implements the LOGIN and MD5-DIGEST smtp authentication mechanisms
 package auth
 
diff --git a/client.go b/client.go
index 1cf263b..e7a3e75 100644
--- a/client.go
+++ b/client.go
@@ -1,3 +1,7 @@
+// SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+//
+// SPDX-License-Identifier: MIT
+
 package mail
 
 import (
diff --git a/client_test.go b/client_test.go
index 09261c6..8b67f88 100644
--- a/client_test.go
+++ b/client_test.go
@@ -1,3 +1,7 @@
+// SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+//
+// SPDX-License-Identifier: MIT
+
 package mail
 
 import (
diff --git a/codecov.yml b/codecov.yml
index c724211..99b8451 100644
--- a/codecov.yml
+++ b/codecov.yml
@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+#
+# SPDX-License-Identifier: CC0-1.0
+
 coverage:
   status:
     project:
diff --git a/doc.go b/doc.go
index 45130d1..e9898cb 100644
--- a/doc.go
+++ b/doc.go
@@ -1,3 +1,7 @@
+// SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+//
+// SPDX-License-Identifier: MIT
+
 // Package mail provides a simple and easy way to send mails with Go
 package mail
 
diff --git a/doc_test.go b/doc_test.go
index 5cfd58f..8a71f11 100644
--- a/doc_test.go
+++ b/doc_test.go
@@ -1,3 +1,7 @@
+// SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+//
+// SPDX-License-Identifier: MIT
+
 package mail_test
 
 import (
diff --git a/encoding.go b/encoding.go
index ebbb54c..3fd20e0 100644
--- a/encoding.go
+++ b/encoding.go
@@ -1,3 +1,7 @@
+// SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+//
+// SPDX-License-Identifier: MIT
+
 package mail
 
 // Charset represents a character set for the encoding
diff --git a/encoding_test.go b/encoding_test.go
index ebef573..5529f91 100644
--- a/encoding_test.go
+++ b/encoding_test.go
@@ -1,3 +1,7 @@
+// SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+//
+// SPDX-License-Identifier: MIT
+
 package mail
 
 import "testing"
diff --git a/file.go b/file.go
index b2e3936..7a558e2 100644
--- a/file.go
+++ b/file.go
@@ -1,3 +1,7 @@
+// SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+//
+// SPDX-License-Identifier: MIT
+
 package mail
 
 import (
diff --git a/file_test.go b/file_test.go
index 0b67147..6c5ca6b 100644
--- a/file_test.go
+++ b/file_test.go
@@ -1,3 +1,7 @@
+// SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+//
+// SPDX-License-Identifier: MIT
+
 package mail
 
 import "testing"
diff --git a/go.mod b/go.mod
index 971a2df..c0569d0 100644
--- a/go.mod
+++ b/go.mod
@@ -1,3 +1,7 @@
+// SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+//
+// SPDX-License-Identifier: MIT
+
 module github.com/wneessen/go-mail
 
 go 1.16
diff --git a/header.go b/header.go
index 3d03409..bb143ad 100644
--- a/header.go
+++ b/header.go
@@ -1,3 +1,7 @@
+// SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+//
+// SPDX-License-Identifier: MIT
+
 package mail
 
 // Header represents a generic mail header field name
diff --git a/header_test.go b/header_test.go
index c9d6dd0..091a1a9 100644
--- a/header_test.go
+++ b/header_test.go
@@ -1,3 +1,7 @@
+// SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+//
+// SPDX-License-Identifier: MIT
+
 package mail
 
 import (
diff --git a/msg.go b/msg.go
index 6d27d0e..30bad37 100644
--- a/msg.go
+++ b/msg.go
@@ -1,3 +1,7 @@
+// SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+//
+// SPDX-License-Identifier: MIT
+
 package mail
 
 import (
diff --git a/msg_nowin_test.go b/msg_nowin_test.go
index 4a4af41..965b6f3 100644
--- a/msg_nowin_test.go
+++ b/msg_nowin_test.go
@@ -1,3 +1,7 @@
+// SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+//
+// SPDX-License-Identifier: MIT
+
 //go:build !windows
 // +build !windows
 
diff --git a/msg_test.go b/msg_test.go
index 3ed7a96..d14a756 100644
--- a/msg_test.go
+++ b/msg_test.go
@@ -1,3 +1,7 @@
+// SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+//
+// SPDX-License-Identifier: MIT
+
 package mail
 
 import (
diff --git a/msg_totmpfile.go b/msg_totmpfile.go
index 0df5248..25d5829 100644
--- a/msg_totmpfile.go
+++ b/msg_totmpfile.go
@@ -1,3 +1,7 @@
+// SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+//
+// SPDX-License-Identifier: MIT
+
 //go:build go1.17
 // +build go1.17
 
diff --git a/msg_totmpfile_116.go b/msg_totmpfile_116.go
index 7f415dd..c911dc6 100644
--- a/msg_totmpfile_116.go
+++ b/msg_totmpfile_116.go
@@ -1,3 +1,7 @@
+// SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+//
+// SPDX-License-Identifier: MIT
+
 //go:build !go1.17
 // +build !go1.17
 
diff --git a/msgwriter.go b/msgwriter.go
index 5bbce3d..78daec7 100644
--- a/msgwriter.go
+++ b/msgwriter.go
@@ -1,3 +1,7 @@
+// SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+//
+// SPDX-License-Identifier: MIT
+
 package mail
 
 import (
diff --git a/msgwriter_test.go b/msgwriter_test.go
index a104bb4..bd1aa4e 100644
--- a/msgwriter_test.go
+++ b/msgwriter_test.go
@@ -1,3 +1,7 @@
+// SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+//
+// SPDX-License-Identifier: MIT
+
 package mail
 
 import (
diff --git a/part.go b/part.go
index 941af9b..d1996d6 100644
--- a/part.go
+++ b/part.go
@@ -1,3 +1,7 @@
+// SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+//
+// SPDX-License-Identifier: MIT
+
 package mail
 
 import "io"
diff --git a/part_test.go b/part_test.go
index 84043f5..3a567b8 100644
--- a/part_test.go
+++ b/part_test.go
@@ -1,3 +1,7 @@
+// SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+//
+// SPDX-License-Identifier: MIT
+
 package mail
 
 import "testing"
diff --git a/sonar-project.properties b/sonar-project.properties
index 90ababa..b5e8e8e 100644
--- a/sonar-project.properties
+++ b/sonar-project.properties
@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+#
+# SPDX-License-Identifier: CC0-1.0
+
 sonar.projectKey=go-mail
 sonar.go.coverage.reportPaths=cov.out
 sonar.externalIssuesReportPaths=report.json
diff --git a/tls.go b/tls.go
index 62414d9..eafc2b5 100644
--- a/tls.go
+++ b/tls.go
@@ -1,3 +1,7 @@
+// SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+//
+// SPDX-License-Identifier: MIT
+
 package mail
 
 // TLSPolicy type describes a int alias for the different TLS policies we allow
diff --git a/tls_test.go b/tls_test.go
index 99f7028..a902e63 100644
--- a/tls_test.go
+++ b/tls_test.go
@@ -1,3 +1,7 @@
+// SPDX-FileCopyrightText: 2022 Winni Neessen <winni@neessen.dev>
+//
+// SPDX-License-Identifier: MIT
+
 package mail
 
 import "testing"