Marius Gologan:
> Is there any standard behavior in respect to 430 4.7.0?
The standard says that this is a soft error, i.e. delivery
may succeed at a different time or server.
> For example, clients such as facebook, messagelabs don't deliver
> messages using TLS constantly.
Me no understand.
> Would they retry immediately with TLS or they will keep rotating IPs until
> one is using STARTTLS?
That is up to the client. It may try TLS on other IP addresses
before falling back to plaintext, or it may fall back to plaintext
immediately (Postfix default behavior). Postfix can be configured
to return mail as undeliverable after trying TLS on other IP addresses
(by setting smtp_delivery_status_filter); that has effect only for
deliveries where TLS is required.
Wietse
