jwhitesell

Registered
Oct 3, 2011
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Root Administrator
I've run into an email deliverability issue I've never seen before. When trying to send mail from an account the mail is rejected by the remote server with the following messages:


SMTP error from remote mail server after MAIL FROM:<[email protected]> SIZE=61649:
550-Verification failed for <[email protected]>
550-Unrouteable address
550 Invalid sender <[email protected]>


I've got SPF and DKIM set up correctly. All deliverability tests I run find no issues.

The recipient's provider said this to their client:
"They have disabled "Allow empty sender address" in the SMTP/AntiSpam
settings. This setting is enabled by default. "

I've looked through the EXIM settings and if there is a setting like that I've missed it.

Any insight into how to solve this? Thanks!
 

jwhitesell

Registered
Oct 3, 2011
4
0
51
cPanel Access Level
Root Administrator
And to expand on this... the address on my server that is being rejected by the remote server IS set up correctly on my server and has no issues with any other external addresses except those hosted by this one provider.

What could cause this valid address on my server to fail an SMTP callout verification? It appears to succeed when I try it.

I've run into an email deliverability issue I've never seen before. When trying to send mail from an account the mail is rejected by the remote server with the following messages:


SMTP error from remote mail server after MAIL FROM:<[email protected]> SIZE=61649:
550-Verification failed for <[email protected]>
550-Unrouteable address
550 Invalid sender <[email protected]>


I've got SPF and DKIM set up correctly. All deliverability tests I run find no issues.

The recipient's provider said this to their client:
"They have disabled "Allow empty sender address" in the SMTP/AntiSpam
settings. This setting is enabled by default. "

I've looked through the EXIM settings and if there is a setting like that I've missed it.

Any insight into how to solve this? Thanks!
 

cPanelLauren

Forums Analyst II
Staff member
Nov 14, 2017
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263
Houston
cPanel Access Level
DataCenter Provider
Hello @jwhitesell

This isn't an exim setting which is why you're not finding it. This is a setting that is specific to the recipient's Anti-SPAM configuration. While more than likely the issue is a sender verification lookup failed due to some configuration issue on the remote server, Per RFC requirements Empty senders must be allowed. This is noted in exim's documentation Exim Specification - 45. Verification of incoming mail and discussed in RFC 1123 - Requirements for Internet Hosts - Application and Support of the RFC documentation.



This is an issue that needs to be addressed on the remote server, it cannot be addressed on your server.

Thanks!