Envelope enhancements

[MattMofDoom]

Hi @nblumhardt,

PR that's intended to follow #81. I figured it would be okay to queue it up for when you get to it 😊

Feature enhancements:

• Add Priority, with optional priority property mapping and default
• CC, BCC, and ReplyTo added as optional envelope options with handlebars template
• Added optional plain text alternate body template
• Enhance email logging

Notes:

• This will close Email+ - Add optional CC and BCC fields #65 and pulls in the final (viable) thoughts from Add SSL validation suppression option #77.
• This is the last set of updates from the mega PR MailKit conversion #78 that we broke into pieces.

[MattMofDoom]

Incorporates the merge of #86 with #81 while preserving the envelope enhancements from this PR, making this a full featured email application.

[MattMofDoom]

Hi @liammclennan and @nblumhardt,

As with #81, merging the changes from #93. This sustains the use of SmtpOptions.GetSocketOptions while retaining the added envelope functionality.

Cheers,

Matt

[MattMofDoom]

Updated dependencies

[MattMofDoom]

App comprising the enhancements from #81 and #83 is currently published to Nuget as https://www.nuget.org/packages/Seq.App.EmailPlus-Enhanced while this is pending review/merge.

This is working well in a production environment. More information on the features was published at https://mattmofdoom.com/seqappemailplus-enhanced-available/