• Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 721
  • Last Modified:

Mail coming from a mxlogic.net host in our network

We have been getting listed on a blacklist because mail is coming from several EHLO names in our network on the same IP.  We have several mail servers, so this is expected.

We are seeing however two listings from the domain mxlogic.net that we are unsure of.  Doing some research it looks to be related to McAfee products, but we are not using any on our mail systems.

Any ideas what this may be?

Also, any issues with having several mail servers all sending out the same IP with different EHLO names?
1 Solution
Who is your ISP?
TacoFlavoredKissesAuthor Commented:
It is a Time Warner pipe
there are servers that check that EHLO names is resolving to the IP where the mail is coming from.  So make sure that you have "A" record for each EHLO name and "A" is pointed to the sending IP
Building an Effective Phishing Protection Program

Join Director of Product Management Todd OBoyle on April 26th as he covers the key elements of a phishing protection program. Whether you’re an old hat at phishing education or considering starting a program -- we'll discuss critical components that should be in any program.

TacoFlavoredKissesAuthor Commented:

Any other thoughts on the mxlogic.net?
I imagine your problem is a bunch of companies are using that anti-spam method of requiring that the reverse PTR records match the name of the mail server sending the mail so using multiple mail servers with different ehlo names is causing the problem.  No shit, right?
I think you need to add an MX record for each mail server to resolve to the correct record on file with your ISP.  For example, if your ISP has your PTR in DNS as xx.xx.x.x Mail.yourdomain.com, that sending IP and FQDN has to match.  Creating an MX record in your DNS for each server, i.e Servername - Mx record - mail.yourdomain.com should fix it, I think.  My head hurts thinking about it and only a couple big companies use this because it's a headache when nobody has their reverse PTR set up correctly, even though they should, and your users all come crying to you that some guy has been sending them important emails but they never get them because your mail server is dropping the connection instantly when the reverse PTR doesn't match and not notifying anybody that the guy is trying to send email.  There are usually no bounceback messages or anything.  My configuration above might need to be tinkered with because I don't know what kind of problems if any, will come up with mulitple MX records pointing to different servers.  If all clients are able to send via any of the SMTP servers then that shouldn't be a problem but I'm not sure about receiving if you have their Outlook profiles configured to pull mail down from mail.yourdomain.com which would be your ExchangeserverA and but DNS is resolving exchangeserverA, B, and C all to mail.yourdomain.com.  
Clear as mud?
Or maybe it would have to be A records and MX records, now that I think about it.  So you would have multiple servers all with the same A record of mail.yourdomain.com as well as internal MX records....I think  I'm confusing myself even.  Sooo...your DNS might have to look like this if it will let you?  Basically, when the mail comes out of your domain, all the email has to match your Reverse PTR so you have to get all your servers to look like no matter which one sends it, all the mail is coming mail.yourdomain.com.

Name                                             Type                                        Data
exchangeserverA                        MX                                        exchangeserverA.yourdomain.com
exchangeserverA                          MX                                       mail.yourdomain.com
exchangeserverB                           MX                                       exchangeserverB.yourdomain.com
exchangeserverB                            MX                                     mail.yourdomain.com
exchangeserverC                           MX                                      exchangeserverC.yourdomain.com
exchangeserverC                            MX                                       mail.yourdomain.com
mail                                                  Host (A)                               192.168.x.x (Ip of exchangeserverA )
mail                                                   Host (A)                              192.168.x.x (ip of exchangeserverB)
mail                                                  Host (A)                               192.168.x.x (ip of exchangeserverC)
mail                                                   MX                                         mail.yourdomain.com
TacoFlavoredKissesAuthor Commented:
That would cause mail to try and flow into the wrong places with the MX record that way.

Our MX record goes to a cluster of Barracudas, and is not evewn the same IP as the one mail gets sent from.  Most filters/mail servers just care that your mail comes from an IP that HAS a reverse DNS entry.  Half the ones I see people sending with are not at all the same as their EHLO.

I think the easier solution may be to change the PAT to send as a different IP for each mail server, and set up reverse DNS for each of them.

It is odd because it has not been an issue in 4 years of sending multiple mail server platforms out the same public.  I think as spammers get craftier the people reporting and black listing are getting more strict.
There ya go.  If you have a group of external IPs available, then that would be easy to get reverse PTRs set up for each server and yes, I see a ton of email where there EHLO doesn't match.  I didn't have a problem with it until recently as well.  I think it was Verizon or somebody that I ran into that was forcing the match and they, in turn, had put us on some blacklists.
TacoFlavoredKissesAuthor Commented:
Still wondering what causes the MX logic ones if anyone else has any insight
TacoFlavoredKissesAuthor Commented:
Not sure if I understand your question correctly. Your outgoing emails are blacklisted because you have several EHLO names due to different mail servers that send all mails out through a single IP, correct?

Could the MXLogic thing be related to using MXLogic outbound filtering which would require a smarthost configured on the mailserver that points to the MXLogic outbound filtering service?
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

Featured Post

Free Tool: SSL Checker

Scans your site and returns information about your SSL implementation and certificate. Helpful for debugging and validating your SSL configuration.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Tackle projects and never again get stuck behind a technical roadblock.
Join Now