Add UseDefaultCredentials

[PrzemyslawKlys]

In SMTP mail UseDefaultCredentials can be called to skip need to provide credentials.

• https://docs.microsoft.com/en-us/dotnet/api/system.net.mail.smtpclient.usedefaultcredentials?view=netcore-3.1

In Send-MailMessage it seems to be turned on by default if there's no login/pass prompt given or at least I think so. Would need to check sources.

• Email "UseDefaultCredentials" PSWriteHTML#156

In MailKit it can be achieved it seems but requires some deep dive

• https://stackoverflow.com/questions/38113437/is-it-possible-to-use-default-network-credentials-with-mailkit-and-exchange
• NTLM with DefaultNetworkCredentials jstedfast/MailKit#332 (comment)

[AvrumFeldman]

Is there any plan on implementing this? It would be very beneficial for situations where we need services to send emails using a local AD integrated SMTP server and don't want to store credentials.

[PrzemyslawKlys]

It is wanted & therefore planned, but I lack time to implement this. But if you have time, feel free to take a bite.

[AvrumFeldman]

@PrzemyslawKlys I looked through the thread from MailKit and it seems that integrated authentication isn't implemented yet even on MailKit due to not being cross compatible.

[PrzemyslawKlys]

@AvrumFeldman it probably never will be cross-compatible, but from what I see jstedfast/MailKit#332 (comment) someone did do it on Windows, which would be enough.

[AvrumFeldman]

@PrzemyslawKlys I didn't realize you are fine with non cross compatibility. I will try to give it a shot over the next week (hopefully).

[PrzemyslawKlys]

@AvrumFeldman any luck?

[AvrumFeldman]

@PrzemyslawKlys what a coincident you are asking now. I've just worked this night a few hours on it and I'm (hopefully) almost done.

[PrzemyslawKlys]

Great - we're only missing this and signing functionality. Looking forward to this!

[PrzemyslawKlys]

Implemented in:

• Rework Mailozaurr to build DLLs on the fly #47

Hopefully will work