All hosts for 'domain.com' have been failing for a long time

gennybeans

Member
Aug 16, 2017
5
0
1
Toronto
cPanel Access Level
Root Administrator
Hi,

I've noticed this has been discussed a few times already, but I can't seem to find a solution. I'm not very well-versed in WHM/VPS hosting at all, as I have normally worked with shared hosting websites. But, we were recently moved to a dedicated server and have since then been experiencing problems with our email.

I have contacted our host and they say everything is properly configured and they cannot seem to pinpoint the issue (or see any errors).

Our biggest problem currently is dealing with this one error with a specific domain. All emails we send to this domain return with the error: all hosts for 'domain.name" have been failing for a long time.

I ran exigrep [email protected] /var/log/exim_mainlog and the error shows there as well.

Code:
2017-08-14 17:20:17 1dftO6-0006Cv-SK ** [email protected] <[email protected]> R=dkim_lookuphost T=dkim_remote_smtp: all hosts for 'domain.name' have been failing for a long time (and retry time not reached)
2017-08-14 17:20:17 1dftO6-0006Cv-SK Completed
2017-08-14 10:20:16 1dfrbk-0004FV-F0 == [email protected] <[email protected]> R=dkim_lookuphost T=dkim_remote_smtp defer (110): Connection timed out
Our host suggested it was an issue on domain.name's end (maybe they have blocked our IP address). This account is about one week old, and from the day we moved over to this server, we have had issues with sending emails to domain.name.

Any ideas? Is our only solution to somehow get in contact with domain.name's IT department to resolve this? Or could something else be causing the issue?

Thanks in advance!
 

cPanelMichael

Administrator
Staff member
Apr 11, 2011
47,884
2,254
463
Hello,

I recommend first using "WHM Home » Networking Setup » Resolver Configuration" to ensure your server uses valid resolvers, as it's possible the use of invalid resolvers is preventing your server from resolving that domain name to a valid IP address.

Thank you.
 

cPanelMichael

Administrator
Staff member
Apr 11, 2011
47,884
2,254
463
Hello,

Does the domain name in-question resolve to the correct address when using the "host" command from your server's command line? EX:

Code:
host domain.tld
Thank you.
 

cPanelMichael

Administrator
Staff member
Apr 11, 2011
47,884
2,254
463
Hello,

You may also want to verify your server can connect over port 25 to the IP address of the remote mail server that domain name resolves to. You can use "telnet" to test this. EX:

Code:
telnet IP 25
Thank you.
 

gennybeans

Member
Aug 16, 2017
5
0
1
Toronto
cPanel Access Level
Root Administrator
Code:
220-user.server.net ESMTP Exim 4.89 #1 Wed, 16 Aug 2017 18:11:47 +0000
220-We do not authorize the use of this system to transport unsolicited,
220 and/or bulk e-mail.
Wow, looks like it's blocked?
When I check the Firewall config in WHM, it shows that 25 is listed under 'Allow outgoing TCP ports'.
 

cPanelMichael

Administrator
Staff member
Apr 11, 2011
47,884
2,254
463
Hello,

That output actually suggests it's not blocked (the 220 code is normal). Could you open a support ticket using the link in my signature so we can take a closer look at why your server is unable to send email to that domain name?

Thank you.
 

cPanelMichael

Administrator
Staff member
Apr 11, 2011
47,884
2,254
463
Hello,

To update, it looks like this was the result of the remote mail server blocking connections from the cPanel server's IP address.

Thank you.
 

Mark Coates

Well-Known Member
Mar 13, 2019
98
12
8
Doncaster
cPanel Access Level
Root Administrator
Hi Sorry for starting this off again, i have an issue for this also but as i can see "the remote server was blocking the connection" this is being blocked for several servers although i have checked on a few blacklist sites for MX and it all appears to be ok. all servers are running cpanel/whm. when an email is sent to gmail it just times out.
 

cPanelMichael

Administrator
Staff member
Apr 11, 2011
47,884
2,254
463
Hi Sorry for starting this off again, i have an issue for this also but as i can see "the remote server was blocking the connection" this is being blocked for several servers although i have checked on a few blacklist sites for MX and it all appears to be ok. all servers are running cpanel/whm. when an email is sent to gmail it just times out.
Can you submit a support ticket so we can take a closer look? Post the ticket number here once it's opened and I'll link this thread to it.

Thank you.