Bump Rnwood.SmtpServer from 3.1.0-ci0426 to 3.1.0-ci0506 (#248)
Bump Rnwood.SmtpServer from 3.1.0-ci0426 to 3.1.0-ci0506 (#248)

Bumps [Rnwood.SmtpServer](https://github.com/rnwood/smtpserver) from 3.1.0-ci0426 to 3.1.0-ci0506.
- [Release notes](https://github.com/rnwood/smtpserver/releases)
- [Commits](https://github.com/rnwood/smtpserver/compare/3.1.0-ci0426...3.1.0-ci0506)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
rnwood/smtp4dev,rnwood/smtp4dev,rnwood/smtp4dev,rnwood/smtp4dev