Hi!
I'm trying to implement some of the features from postscreen. First of
them is sending multitiline smtp banner with delay between lines [1].
It looks as below:
Connected to xyz..
Escape character is '^]'.
220-mail.xyz.net ESMTP
ehlo mejor.pl
250-mail.xyz.net
250-SIZE 51200000
250-VRFY
250-ETRN
250-STARTTLS
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 DSN
mail from:<spam@???>
250 2.1.0 Ok
rcpt to:<xxx@???>
550 5.5.1 Protocol error
So my too fast "ehlo" makes that after "rcpt to" mail will be rejected.
I suspect it will be completely impossible to do it. But maybe such poor
PREGREET test would be possible without many effort in exim code?:
acl_smtp_connect = acl_check_connect
acl_check_connect:
warn
message = 220-mail.xxx. ESMTP
warn
delay = 5s
warn
message = 220 mail.xxx. ESMTP go on dude
And if protocol error appears let Exim rejects email at this moment.
What about adding feature allowing temporary ignoring
protocol/sychronization errors (e.g. ignore_protocols_error=1) and
putting information about such incident into expansion item?
Regards
Marcin
[1] -
http://www.postfix.org/POSTSCREEN_README.html#before_220