[CentOS] Sendmail timout errors

[mouss]

Denis Croombs wrote:
>> Denis Croombs wrote:
>>     
>>> I have 2 Centos servers that are currently giving me grief,
>>>
>>> I am getting the error:-
>>>
>>> SYSERR(root): timeout writing message to mail.server.co.uk
>>>
>>> Resource temporarily unavailable
>>>
>>> This is on both servers
>>>       
>>> Any clues ?
>>>       
>> Yes, your MTAs seem to have a problem writing to 
>> mail.server.co.uk, which is why the connection gets a timeout 
>> after some time.
>>
>> Which is astonishing, as there is no SMTP server listening on 
>> that host, so there should be a temporary error - but not the 
>> one you are getting.
>>
>> Well, maybe they had a problem with mail.server.co.uk and are 
>> fixing the problem at the moment.
>>
>>     
> Hi 
> Sorry, I used mail.server.co.uk as an example, it is happening on approx 10
> or so servers.
>   

There are many possibilities here, and obfuscating the remote mail 
server doesn't help reduce the list of possibilities...

if you can send to these servers, but only get the timeout few times, 
then they are overloaded so your server will need to retry later.

if you can never send to these servers, they may be blocking you (this 
could happen if they believe that you are in residential block).

PS. There is a dns mismatch on one of your mail servers:

# host 66.98.180.26
26.180.98.66.in-addr.arpa domain name pointer mail.deniscroombs.org.
# host  mail.deniscroombs.org
mail.deniscroombs.org has address 209.139.208.133