Thursday, November 22, 2012, 16:06
Category: General
Solution ID: 00000187
My PerfectMail server is not accepting email from the Internet? What can I do to diagnose the problem?
PerfectMail™ may stop accepting e-mail for a number of reasons. Fortunately, PerfectMail runs a periodic validation script that checks for the most likely reasons and displays error messages and warnings on the PerfectMail Dashboard. It there is a problem with e-mail delivery, check the dashboard first.
A server's hostname is the name that it knows itself as. This is different than naming in DNS or any other mechanism. It is the locally defined name.
Your PerfectMail product must have a resolvable, fully qualified hostname; e.g. perfectmail.mydomain.com. There must be a domain portion to the hostname of your PerfectMail server.
This hostname must be resolvable in DNS. Mail servers will look-up server names in DNS as a validation mechanism. Not having a resolvable hostname can cause problems.
If this is not possible to use resolvable DNS names you can use the .localdomain domain; e.g. perfectmail.localdomain.
The PerfectMail configuration scripts try to mitigate the creation of partial hostnames by appending all single word hostnames (e.g. "myhost") with the ".localdomain" top-level-domain (e.g. "myhost.localdomain"). The ".localdomain" top-level-domain is "known" and will not be validated against DNS.
Your PerfectMail hostname must be unique. Often, mail servers will refuse to relay e-mail through mail servers with the same hostname. This is done to prevent endless e-mail delivery loops.
PerfectMail absolutely needs to be able to perform DNS resolution. PerfectMail will refuse to accept e-mail from domain names that do not exist in the DNS space. If DNS is not resolvable then e-mail will not flow.
DNS is also used for a number of validation tests including look-ups on many RBL sites. Not having the ability to perform DNS look-ups severely impairs PerfectMail's ability to filter e-mail.
Memory constraints are the most likely cause of server problems. PerfectMail must have sufficient resources (i.e. memory, CPU and disk) to run. If the server uses all memory and swaps to disk the system performance will slow down significantly. If your server appears to be running slow, check the memory usage and add memory as appropriate.
If the hard disk becomes full PerfectMail will stop accepting e-mail. A nightly script prunes old data to ensure a safe amount of free disk to prevent this from happening.
When the "load average" of the server is greater than 12 (i.e. 12 processes waiting for the CPU) our Mail Tranpsort Agent (MTA) will stop accepting new e-mail connections. This behavior prevents the PerfectMail server from crashing. With a high server load your server is not realistically able to process mail in any case as pushing the load average past 12 can put the server in an unresponsive state.
In any case, if your server is performing sub-optimally, you will likely need to review your resource usage and increase resources as appropriate. PerfectMail provides reports on its web interface to assist you with this assessment. Please refer to the following reports:
Tags: configuration, settings, antispam, error, connectivity, e-mail
Link to this article: https://perfectmail.com/kb/not_accepting_email
Updated: Thursday, November 22, 2012, 16:06
-- David Rutherford
Last modified: 2013-10-11, 12:21
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