Update settings for Strato

[cketti]

They removed support for CRAM-MD5 and don't support any other encrypted authentication methods.

See https://www.strato.de/faq/mail/externes-e-mail-programm-mit-strato-e-mail-adresse-nutzen/

(I am a customer and was notified of this via email)

[babolivier]

I can see a few opportunities for drive-by improvements to this config:

• adding https://www.strato.de/faq/mail/externes-e-mail-programm-mit-strato-e-mail-adresse-nutzen/ as the documentation ref
• changing the SMTP settings to match their documentation (we've got STARTTLS on port 587, they've got SSL/TLS on port 465)

[cketti]

I added the link to the documentation to the config.

There are two SMTP entries. The first one uses TLS (port 465), the second one STARTTLS (port 587). A couple of other configs also contain multiple entries for the same protocol. The general idea is that clients that don't support the first one hopefully support the second one. So I'd like to leave it like this for now.

However, I don't think any modern email client can get away with only supporting one of TLS or STARTTLS. So multiple entries are redundant.
I'll try to find some time to write up a proposal for a policy document on what we want to include in a provider config.

[babolivier]

Ah, somehow I missed we already had the non-STARTTLS entry, my bad.