Trouble sending email to .mil and .gov clients.

Question

Trouble sending email to .mil and .gov clients.

TCI Administrator 11

We have several clients behind the .gov and .mil firewalls. Some of my users have no problem sending and receiving, but a couple, in particular, can not consistently send messages. I've used a third party service to evaluate our DKIM, SPF, etc settings and still have problems. Any knowledge out there that could shed light on this most frustrating problem?

Steve

Anonymous

2023-11-13T08:07:26.21+00:00

Hello TCI
Is it convenient for you to provide more information? Any error messages or log information when sending fails?
TCI Administrator 11 Reputation points

2023-11-13T16:25:18.3466667+00:00

Thanks for replying, we are notified that messages are not delivered after a few days with a followup phone call. The MS Message Trace shows the message was delivered to the server. Beyond that, no idea. My DKIM, SPF, DMARC, TLS, are all compliant. Just wondering if there is a DOD standard (encryption, etc) requirement that I am missing. The most frustrating aspect though, some of my users get through and others don't...emailing the same individual. What I know works is calling the person to work with their Communications element to "allow" TRUST of name by name. That is an embarrassing load to ask of people we email regularly.
Claude Spears 0 Reputation points

2025-01-01T18:32:17.93+00:00

From what we know; the DoD/.MIL is blocking a range of IPs that are used on the email server(s) your mailbox is associated with. This is why the issue has been on-going for so long; it is because they have not yet corrected the problem from their end. We are making every effort and attempt to rectify this issue as soon as possible.

With the above stated, we are also requesting that if customers have any contacts at your disposal within .MIL, please have them check and unblock the following IPs:

OX/Vade outbound mta:

135.148.117.228/30

135.148.117.232/30

135.148.117.236/30

135.148.152.168/30

15.204.3.4/30

15.204.3.8/30

15.204.3.12/30

15.204.33.72/30

Got this from Network Soultions

2 answers

Your answer

Anonymous

2023-11-13T08:07:26.21+00:00

Hello TCI
Is it convenient for you to provide more information? Any error messages or log information when sending fails?
TCI Administrator 11 Reputation points

2023-11-13T16:25:18.3466667+00:00

Thanks for replying, we are notified that messages are not delivered after a few days with a followup phone call. The MS Message Trace shows the message was delivered to the server. Beyond that, no idea. My DKIM, SPF, DMARC, TLS, are all compliant. Just wondering if there is a DOD standard (encryption, etc) requirement that I am missing. The most frustrating aspect though, some of my users get through and others don't...emailing the same individual. What I know works is calling the person to work with their Communications element to "allow" TRUST of name by name. That is an embarrassing load to ask of people we email regularly.
Claude Spears 0 Reputation points

2025-01-01T18:32:17.93+00:00

From what we know; the DoD/.MIL is blocking a range of IPs that are used on the email server(s) your mailbox is associated with. This is why the issue has been on-going for so long; it is because they have not yet corrected the problem from their end. We are making every effort and attempt to rectify this issue as soon as possible.

With the above stated, we are also requesting that if customers have any contacts at your disposal within .MIL, please have them check and unblock the following IPs:

OX/Vade outbound mta:

135.148.117.228/30

135.148.117.232/30

135.148.117.236/30

135.148.152.168/30

15.204.3.4/30

15.204.3.8/30

15.204.3.12/30

15.204.33.72/30

Got this from Network Soultions

Answer 1

Anonymous

Hello TCI,

Yes, you can try encryption. .gov and .mil domain names may have additional security requirements or restrictions that may cause your email to be blocked or delayed. Blocked by a spam filter or the email was flagged as suspicious due to the content or attachments in the email.

It is recommended that you contact the IT departments of these organizations. They may be able to provide you with more information about their email policy and any specific requirements for incoming email.

Regards

Shaofan

thank you for your time and patience throughout this issue.

If the information helped address your question, please Accept the answer. This will help us and also improve searchability for others in the community who might be researching similar information.

TCI Administrator 11 Reputation points

2023-11-15T14:28:11.44+00:00

thanks for your input. why did this change all of the sudden? until Jun of 23, we did not have issues with .gov and .mil. seems random by organization inside the .gov and .mil. I cannot call all of the individual organizations and ask for their specific nuances. there has to be a global fix. Encryption seems logical. Is that just using the "Encryption" button offered in the Outlook app? or something more difficult to deploy over several users and computers?

Thanks again for your guidance,

Steve
Anonymous

2023-11-17T09:52:24.6233333+00:00

Hello Steve

You mentioned "The MS Message Trace shows the message was delivered to the server." Is that from the sender or the recipient?
If the message has been delivered to the server, you need to ask the recipient to check the junkfolder or other folders that may be routed, and also check whether it has entered the blacklist.
Arend von der Lieth 0 Reputation points

2024-04-09T17:16:11.06+00:00

FWIW, we are experiencing the same issue as the OP: starting mid-November, we see a 50% failure rate for emails to .mil (which previously went through w/o problems). Incoming emails as well as outgoing emails to all other domains still work flawlessly. I read elsewhere that @army.mil be hosted by Microsoft, so I would expect to see some better and more detailed troubleshooting advice.

Answer 2

From what we know; the DoD/.MIL is blocking a range of IPs that are used on the email server(s) your mailbox is associated with. This is why the issue has been on-going for so long; it is because they have not yet corrected the problem from their end. We are making every effort and attempt to rectify this issue as soon as possible.

With the above stated, we are also requesting that if customers have any contacts at your disposal within .MIL, please have them check and unblock the following IPs:

OX/Vade outbound mta:

135.148.117.228/30

135.148.117.232/30

135.148.117.236/30

135.148.152.168/30

15.204.3.4/30

15.204.3.8/30

15.204.3.12/30

15.204.33.72/30

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Trouble sending email to .mil and .gov clients.

2 answers

Your answer