Bump github.com/mrz1836/postmark from 1.6.1 to 1.6.3

Bumps [github.com/mrz1836/postmark](https://github.com/mrz1836/postmark) from 1.6.1 to 1.6.3.
- [Release notes](https://github.com/mrz1836/postmark/releases)
- [Changelog](https://github.com/mrz1836/postmark/blob/master/.goreleaser.yml)
- [Commits](mrz1836/postmark@v1.6.1...v1.6.3)

---
updated-dependencies:
- dependency-name: github.com/mrz1836/postmark
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

go.mod

@@ -25,7 +25,7 @@ require (
 	github.com/mattn/go-runewidth v0.0.15
 	github.com/mattn/go-sqlite3 v1.14.19
 	github.com/mhale/smtpd v0.8.2
-	github.com/mrz1836/postmark v1.6.1
+	github.com/mrz1836/postmark v1.6.3
 	github.com/pkg/term v1.1.0
 	github.com/refaktor/go-peg v0.0.0-20220116201714-31e3dfa8dc7d
 	github.com/refaktor/liner v1.2.6

go.sum

@@ -137,8 +137,8 @@ github.com/mattn/go-sqlite3 v1.14.19/go.mod h1:2eHXhiwb8IkHr+BDWZGa96P6+rkvnG63S
 github.com/mhale/smtpd v0.8.2 h1:rHKOMHeFoDvcq8Na9ErCbNcjlWTSyGtznOmJpWsOzuc=
 github.com/mhale/smtpd v0.8.2/go.mod h1:MQl+y2hwIEQCXtNhe5+55n0GZOjSmeqORDIXbqUL3x4=
 github.com/montanaflynn/stats v0.0.0-20171201202039-1bf9dbcd8cbe/go.mod h1:wL8QJuTMNUDYhXwkmfOly8iTdp5TEcJFWZD2D7SIkUc=
-github.com/mrz1836/postmark v1.6.1 h1:UHAs9WuZEBZj12MdZ/iVRyoC4tq3ODTdYhE17OhJeJ4=
-github.com/mrz1836/postmark v1.6.1/go.mod h1:6z5MxAH00Kj44owtQaryv9Pbqp5OKT3wWcRSydB0p0A=
+github.com/mrz1836/postmark v1.6.3 h1:g5Zv6hGZfqTR79Xb7my5O1aVuiBxWQ0jI2jFzu+Ou9k=
+github.com/mrz1836/postmark v1.6.3/go.mod h1:6z5MxAH00Kj44owtQaryv9Pbqp5OKT3wWcRSydB0p0A=
 github.com/mschoch/smat v0.2.0 h1:8imxQsjDm8yFEAVBe7azKmKSgzSkZXDuKkSq9374khM=
 github.com/mschoch/smat v0.2.0/go.mod h1:kc9mz7DoBKqDyiRL7VZN8KvXQMWeTaVnttLRXOlotKw=
 github.com/pkg/term v1.1.0 h1:xIAAdCMh3QIAy+5FrE8Ad8XoDhEU4ufwbaSozViP9kk=