Issue Remote Server returned '550 Recipient verification failed

[Meer-Web]

Hi All,

I'm getting some bounces from customers when I'm mailing towards them, also the other way arround.
They get bounces when mailing me.

Remote Server returned '550 Recipient verification failed

I have investigated this issue but cannot find the problem.
It seems my email address does not exist, but its working fine. This is caused by a Sender Callback check.
I cannot find the problem why it does not work for specific customers as all tests from mxtoolbox are ok.

Does anybody have experience or a resolution for this issue?

 

[Bitpalast]

- Does the domain have a valid PTR (reverse domain name resolution) record?
- Does it have an SPF record and is the host authorized to send mail for the domain you are sending from?
- Does the HELO domain of the SMTP server resolve to the IP address of the SMTP server?

 

[Meer-Web]

- Does the domain have a valid PTR (revery domain name resolution) record?
- Does it have an SPF record and is the host authorized to send mail for the domain you are sending from?
- Does the HELO domain of the SMTP server resolve to the IP address of the SMTP server?

Hi Peter,

Yes, I have a valid SPF, HELO domain matches and PTR record.
Its just that the remote server does a callback and cannot verify that my FROM address exists which results in a failure.

 

[speedbird]

Hi Peter,

Yes, I have a valid SPF, HELO domain matches and PTR record.
Its just that the remote server does a callback and cannot verify that my FROM address exists which results in a failure.

Seems I have exactly the same problem here:
https://talk.plesk.com/threads/mailserver-says-450-unverified-adress.341707/

only my return code is a 450 instead.
Kind of helpless here... Did you find a solution?

 

[Meer-Web]

No not yet. Only thing I see is that when I telnet to the server from linux it is working fine, but as soon as I telnet from my desktop (windows) it doesn't understand any commands.
Maybe this is one of the reasons but I'm not sure. I only have this issue with a couple of contacts.