EHLO: different size allowed, from different servers to ext

Hi,

When I telnet to an external SMTP server from different servers on our network. EHLO answers with different allowed mail sizes. 30Mb from server 1, only 3Mb from another server.

EXAMPLE to yahoo SMTP server:

telnet 67.28.113.10 25

EHLO

answer if I try it from our server 1:

220 mta177.mail.re2.yahoo.com ESMTP YSmtp service ready

ehlo

250-mta177.mail.re2.yahoo.com

250-8BITMIME

250-SIZE 31981568

250 PIPELINING

anwer if I try it from one of our other servers:

220 mta162.mail.re2.yahoo.com ESMTP YSmtp service ready

ehlo

250-Requested mail action okay, completed

250-8BITMIME

250 SIZE 3072000

quit

221 mta162.mail.re2.yahoo.com

Does anyone know what the reason can be? Thank you very much for your help.

Best Regards,

Nico

1 Reply

I've found it:

It was a rule on the firewall. (Inbound = very strange since it is outgoing).

another thing that is very strange:

Why does the external SMTP server answers with the size that our FW allows, and not with what is allowed on -in this example yahoo's SMTP server?

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