richard lucassen:
> Hello list,
>
> For a few reasons I use an outgoing postfix as smarthost. The source
> mailserver is an exchange. Before the postfix server was in use,
> sending mail to a bunch of recipients at a domain which is hosted by
> outlook.com was no problem. When the mail passes through postfix, mail
> to many recipients at a domain hosted by outlook.com is delayed and this
> is the message I see in the queue:
>
> -Queue ID- --Size-- ----Arrival Time---- -Sender/Recipient-------
> EA57C5F8D9 7094 Mon May 15 14:41:09 u...@example.com
> (host 358619467.mail.outlook.com[213.199.154.106] said: 452 4.5.3 Too
> many recipients (AS780090)
> [AM5EUR03FT055.eop-EUR03.prod.protection.outlook.com] (in reply to RCPT
> TO command))
>
> Searching a bit I found this setting:
>
> smtp_destination_recipient_limit
>
> This defaults to 50. Is this the right parameter to adjust?
Maybe. In the fight against spam, mail server operators are not
exactly famous for providing accurate error messages.
The SMTP standard says the server should accept 100 or more recipients
in the same MAIL FROM transaction, and it specifies no limit on the
number of MAIL FROM transactions in the same SMTP session. Mail
operators on the other hand may do all kinds of arbitrary things.
Working around this may involve a combination of Postfix rate_delay
and other settings. Donate your eyeballs to your preferred search
engine to find out what other people do. My domain is too small
to provide meaningful experience in this respect.
Wietse
