Hi, hm ... the message is quite new to me, but it seems that somebody wants to tell you that your mailserver is open for relaying and you should close it ... the thing about the increasing mailboxes seems to be an identification for running spam-actions via your mail-server. Normaly, if your Mailserver is used for spaming, the messages to the administrator for "undeliverable mails" will increase also. The reason is, that spammers normaly are not very carefull in proofing the email addresses they want to reach. So if there are old addresses or deleted addresses in the "spam list", which are undeliverable, the admin of the mail server used will receive the "undeliverable messages" from the postmaster or the MTA, but when he opens the message he will see a sender and receiver which he didnt know ... So you should close the possibility to use your mailserver for sending mails from outside your domain (or outside your IP range) ... that means blocking SMTP for "not local users" or "not allowed users (if WAN Users are also using your mailserver for sending - big company for example)" ... cu Michael Nikos Psarrakis wrote:

Whenever i give a ps-ef|grep send on my e-mail server i occasionally get the following address

"fix.your.open.relay.or.die".

Besides, the queues seems to increase their sizes rapidly with no particular reason.

Is there any idea?

We believe that someone is trying to block our e-mail server.

Thanks in advance i remain....