501 Domain must resolve (in reply to MAIL FROM command)

[arto]

Hi.
We have an error with a various domains with sending e-mails. Our server returns with the message :
Jan 22 10:15:00 correu postfix/smtp[5100]: 5F17239EC02C: to=, relay=mail.tenisgimeno.com[86.109.125.213]:25, delay=0.18, delays=0/0/0.1/0.07, dsn=5.0.0, status=bounced (host mail.tenisgimeno.com[86.109.125.213] said: 501 Domain must resolve (in reply to MAIL FROM command))
I don't know what is the problem. Any idea?

[phoenix]

[quote user="arto"]I don't know what is the problem. Any idea?[/QUOTE]You could search the forums (or the internet) and find tons of information about the returned error. Do you know what a reverse DNS record is and why it's important? You apparently don't have the correct one for your server and some mail servers will reject mail under those circumstances. I'd suggest you try some of the internet sites to verify your reverse DNS record then get it corrected.

[arto]

Thanks phoenix. But i have correctly the reverse resolution for my MX. I think so...
help

[kruon]

[quote user="arto"]Thanks phoenix. But i have correctly the reverse resolution for my MX. I think so...
help[/QUOTE]
If I'm reading that right, someone is using user.name@example.local as sender, and for good reason, your server doesn't like it.

The sender needs to have valid address and server is rejecting it because the example.local cannot be resolved to anything sane.