Update reply-to email address section

[karlchillmaid]

What problem does the pull request solve?

Corrects inconsistencies in the language and formatting of the reply-to email address section.

Checklist

• [x] I’ve used the pull request template
• [ ] I’ve written unit tests for these changes
• [ ] I’ve update the documentation (in DOCUMENATION.md and CHANGELOG.md)
• [ ] I’ve bumped the version number (in src/Notify/Notify.csproj)