Blocked by hotmail due to smtp!

[ganastasiou]

Hello,

I have the following situation, someone tried to use my smtp for relay using his hotmail account. There were a lot of attempts but relay access is disabled(or at least needs authentication). Today a client of mine told me that he cannot send to hotmail accounts. This blocklist behaviour by hotmail was triggered because someone tried to use my smtp for relay.

The logs says that

Relay access denied

. But there were too many attempts. How can i prevent this from happening? And the server wasn't used for spam it was denied, why did they blocklist my IP?

Thanks in advance

 

[Faris Raouf]

Hotmail (Microsoft) will not put you on their blocklist UNLESS the IP address of your server has been sending out spam. Not "attempting" - definitely sending OR if IP addresses in the immediate neighbourhood of yours has been sending spam.

It doesn't matter how many times someone attempts to send spam - if relaying is denied then nothing bad happens, so I am a little confused by your post.

Also when someone tries to send spam but is denied, other than the username used to authenticate, no address is logged. So I don't understand what you mean when you say "someone tried to use my smtp for relay using his Hotmail account". If they tried to authenticate with a username that was in the form of a Hotmail email address then it would never, ever work.

Whatever the situation is, what you need to do is get the full bounce message your client received and read what it says in detail to find out what the problem is.

You should also check this: http://mail.live.com/mail/troubleshooting.aspx
Note that Hotmail, live.com, msn.com and outlook.com are all Microsoft products and all use the same blacklists and policies.

Having been blacklisted by Microsoft in the past, I have to tell you that it is very difficult to communicate with them. I had to go to a great deal of effort to try to figure out what their problem was and what to do to make them happy. It turned out that we had some users sending a very, very small volume of messages to Microsoft-hosted addresses, and some of them were being marked by the recipients as spam, even though they were not really spam in any way. We also had some users who were forwarding messages from their hosted email to their Hotmail accounts, and tagging any real spam they received as spam (which, since it was forwarded via our servers, understandably makes our systems the offending IP as far as Microsoft was concerned). We had to fill in a lot of forms, set up a feedback loop and various other things, and once that was done all was well.

 

[ganastasiou]

Hotmail (Microsoft) will not put you on their blocklist UNLESS the IP address of your server has been sending out spam. Not "attempting" - definitely sending OR if IP addresses in the immediate neighbourhood of yours has been sending spam.

It doesn't matter how many times someone attempts to send spam - if relaying is denied then nothing bad happens, so I am a little confused by your post.

Also when someone tries to send spam but is denied, other than the username used to authenticate, no address is logged. So I don't understand what you mean when you say "someone tried to use my smtp for relay using his Hotmail account". If they tried to authenticate with a username that was in the form of a Hotmail email address then it would never, ever work.

Whatever the situation is, what you need to do is get the full bounce message your client received and read what it says in detail to find out what the problem is.

You should also check this: http://mail.live.com/mail/troubleshooting.aspx
Note that Hotmail, live.com, msn.com and outlook.com are all Microsoft products and all use the same blacklists and policies.

Having been blacklisted by Microsoft in the past, I have to tell you that it is very difficult to communicate with them. I had to go to a great deal of effort to try to figure out what their problem was and what to do to make them happy. It turned out that we had some users sending a very, very small volume of messages to Microsoft-hosted addresses, and some of them were being marked by the recipients as spam, even though they were not really spam in any way. We also had some users who were forwarding messages from their hosted email to their Hotmail accounts, and tagging any real spam they received as spam (which, since it was forwarded via our servers, understandably makes our systems the offending IP as far as Microsoft was concerned). We had to fill in a lot of forms, set up a feedback loop and various other things, and once that was done all was well.

Hmm the cause of the blocklist was namespace mining. They told me they received a lot of RCPT TO and were too few of them that were received. I checked the logs to but the only thing that was weird was that a hotmail account tried to use my smtp server for relay with the same sender and recipient([email protected]), but the smtp didn't allow relay.

 

[Lloyd_mcse]

You can check yourself against over 100 blacklists at http://mxtoolbox.com, I find it handy so thought i'd share.

Good luck

 

[ganastasiou]

You can check yourself against over 100 blacklists at http://mxtoolbox.com, I find it handy so thought i'd share.

Good luck

Thanks, i prefer http://multirbl.valli.org/ it's better and more complete. I have no blacklist, that's why i am trying to understand why did they blocklist my ip. Because i understand that for the attempted tries for relay, when they are denied, hotmail wouldn't have anything on their logs.

 

[ganastasiou]

You can check yourself against over 100 blacklists at http://mxtoolbox.com, I find it handy so thought i'd share.

Good luck

Thanks. I prefer http://multirbl.valli.org/, it's more complete. But i am not blocklisted anywhere, and the logs didn't show anything weird. Today i set up fail2ban to protect sasl and postfix.

 

[Lloyd_mcse]

Thanks for the tip, bookmarked for later use