0
votes
1answer
28 views

Setting Up PTR to correct “Forged hostname” error

Our e-mails mostly get through fine, but here's an error I haven't seen before. Diagnostic-Code: smtp;550 5.7.1 ... Forged hostname for 66.132.221.45 >which resolves as www.medialabinc.net but ...
2
votes
1answer
934 views

Having trouble interpreting mail log DNS errors

I have a postfix mail server on Debian. A client of mine just informed me that they were unable to send an email to me and it appears that there is a problem with their mail server. I would like to ...
2
votes
1answer
8k views

451 #4.1.8 Domain of sender address does not resolve

When sending out email to xxx@terremark.com through my own SMTP server (mail.sarit.be), the receiving mail server replies with: 451 #4.1.8 Domain of sender address <xxx@sarit.be> does not ...
2
votes
1answer
7k views

Domain of sender address does not resolve (in reply to MAIL FROM command)

When sending out emails with postfix I sometimes get this error: 451 #4.1.8 Domain of sender address <user@mydomain.tld> does not resolve (in reply to MAIL FROM command) The domain ...
0
votes
1answer
715 views

Emails from Hotmail to our domain always bounce

Now this is a rather odd problem with emails from any hotmail address being bounced by one of our domains. First off, I can guarantee that this is not a spam filter issue as there is defintitely ...
0
votes
1answer
374 views

IIS6 SMTP service attempts to send mail to domain root A records instead of MX, why?

Getting some random bouncebacks on e-mail processed through an IIS6 SMTP service acting as a smart host (outbound mail gateway). Configuration example... For domain example.com we there is a Root A ...
-1
votes
2answers
250 views

What exactly should HELO say?

I have MX records setup at mail.domain.com and my domain is visible through domain.com I am sending email via PHP PEAR Mail package. This page claims I can change: The value to give when sending ...
2
votes
1answer
371 views

Is it possible to check the Apache user's mail?

I'm trying to debug a problem with sending mail on a Red Hat/Apache server. When I send email from the command line using sendmail -t, I get bounce-back emails with messages like this: The original ...
0
votes
1answer
5k views

Email bouncing because IP name lookup failed, but I can see rDNS

I am seeing a lot of email bouncing from my server... the bounce messages indicate that the IP does not have reverse DNS set up, but I can see valid rDNS records when I query it on my local machine. I ...
0
votes
1answer
406 views

Email being bounced if email recipient domain name == local domain

I have a website where the domain uses an external mail server (defined by mail.mydomain.com and the MX record). An example email address is johndoe@mydomain.com. Whenever the server sends a ...
1
vote
3answers
421 views

How to make sure that in case of our mail server being unreachable (connection down) mail still gets queued and resent once it's back up?

We have had some issues with losing internet connection once in a while. Normally that would mean our mail server is unreachable and incoming email is bouncing. We've set up MX Backup (second MX ...
1
vote
2answers
181 views

Our domain is being appended onto emails addresses that are sent from our server, why?

Our app sends out many types of email notifications. On some occasions, we see that the email addresses are getting our domain appended to them. e.g. michael@gmail.com turns into ...