Mail with identical sender and recipient addresses

cney · #1 (**permalink**) 07-10-2009, 08:28 AM

Good Morning,

I've got a problem with mail routing or spam, perhaps someone has an idea:

A mail has to be send from an application from xy@company.com to xy@company.com (identical addresses). This mail is relayed by server A (not responsible for this domain) and server B (MX-record for this domain) doesn't accept this mail. There is no SPF-record for company.com and for various reason I can't contact the administrator of server B.

What could be the reason for blocking this mails? Is it possible that a spam rule blocks mails which have identical sender and recipient?

Thanks a lot!

BAlfson · #2 (**permalink**) 07-10-2009, 12:45 PM

Is thiis a question about Astaro? Do you have Astaro SMTP log entries concerning one such email?

Read about "Reverse DNS" records and checking; that will help you understand how Astaro checks arriving emails.

Cheers - Bob

Billybob · #3 (**permalink**) 07-10-2009, 07:18 PM

The remote admin might be using BATV. Or he might simply be blocking all emails *@company.com to stop back scatter since there isn't any logical reason that he should get an email sent to him by his own domain. I do that on my backup mx for spam.

khardeveld · #4 (**permalink**) 07-11-2009, 08:49 PM

If you know that the mail isn't accepted, is this because you get a bounce message? If so, this mostly states a reason for the bounce (for example: 550 Relay denied). This helps a lot in telling what is going on, so if you could provide this info....

cney · #5 (**permalink**) 07-15-2009, 02:44 PM

Thank you for your answers, I got more detailed information:

Server B is an Astaro 7.403 with a Sender Blacklist entry like *@company.com, so no incoming mail will be delivered if the senders address is an internal @company.com address. Additional to that there is an exception rule for this special application, that this host is excepted by all filters (e.g. spam filter).

Although I set this exception, the mail returned to sender with the following information:

<abc@company.com>: host xyz said: 550 Access denied
(sender blacklisted) (in reply to RCPT TO command)

Is it possible, that I can't ignore the senders blacklist by an exception? Does anyone have another idea to solve that problem?

thanks a lot!