SMTP and TLS

[#1]

I get my email from Plusnet by them forwarding it to my SMTP server.
I've been tweaking my smtp configuration to stop most of Korea Taiwan and China from attempting to use it as a mail relay. They can't as its screwed down nice and tight but I was playing round with various smtpd parameters and I noticed the following in my mail log:
[tt]Feb 26 14:03:17 kodaly postfix/smtpd[20672]: connect from relay.ptn-ipout01.plus.net[212.159.7.35]
Feb 26 14:03:17 kodaly postfix/smtpd[20672]: setting up TLS connection from relay.ptn-ipout01.plus.net[212.159.7.35]
Feb 26 14:03:17 kodaly postfix/smtpd[20672]: Anonymous TLS connection established from relay.ptn-ipout01.plus.net[212.159.7.35]: TLSv1 with cipher RC4-SHA (128/128 bits)
Feb 26 14:03:18 kodaly postfix/smtpd[20672]: 04C53A4AA56: client=relay.ptn-ipout01.plus.net[212.159.7.35]
[/tt]
Which was nice
So if anyone else is running their own email server with Plusnet forwarding to it then its worth seeing if TLS is working for you.
PN do not seem to support TLS on their smtp servers though

[#2]

I use MX delivery to my IP, but have to relay outgoing mail via PNs servers.
We often find the relay rejects legitimate mail with various errors (address unknown, not authorised etc) but upon retrying with exactly the same address (its stored in our company address book for a number of group HQ staff) it works.
Often it takes two or three attempts before the relay will actually forward the mail.

Fundamentally I'm not convinced that PN have ever managed to get email 'right', despite various different attempts which have come ever closer.

[#3]

Oddly enough I've never seen PN reject outgoing emails. Sometimes I've seen it get stuck in a queue on my server but usually forwarding to relay.plus.net works pretty much instantly