M365 / Outlook Online email rejected by mx.mymts.net

Question

M365 / Outlook Online email rejected by mx.mymts.net

John Calvert 0

Whenever I reply using Outlook app / Outlook Online (M365) to a family member email originating from MTS the latter rejects my reply. I’ve tries rephrasing the msg, it’s a simple personal msg, nothing helps. This has been occurring for months. Seems like MTS doesn’t trust MS. What to do?

mx.mymts.net rejected your message to the following email addresses:

XXX (******@mymts.net)

Your message couldn't be delivered because the recipient's email server (outside Office 365) suspected that your message was spam.

mx.mymts.net gave this error:
Remote server returned message detected as spam -> 554 5.7.1 [VI-102] Message blocked due to spam content in the message.

SokiGuo-MSFT 31,826 Reputation points Microsoft External Staff

2023-08-11T08:25:18.74+00:00

Hi

I’m checking how the things are going on about this issue. Whether the answer helps you?

If there is any problem with this issue, feel free to let me know.

1 answer

Your answer

SokiGuo-MSFT 31,826 Reputation points Microsoft External Staff

2023-08-11T08:25:18.74+00:00

Hi

I’m checking how the things are going on about this issue. Whether the answer helps you?

If there is any problem with this issue, feel free to let me know.

Answer 1

Vasil Michev 128.4K MVP Volunteer Moderator

Does this happen when you send a message directly (i.e. a new message, no reply) or just when replying?

Generally speaking, it's up to the recipient's email system to decide how messages from Microsoft 365 are processed. They can outright block them, perhaps due to the service being abused by spammers, and there's nothing you can do about it. That said, in most cases you can ask the recipient to "whitelist" your address, which can help delivery in some cases. They can also ask open a ticket on their end to get this looked into, if appropriate.

John Calvert 0 Reputation points

2023-08-08T19:51:55.5+00:00

Happens same when I compose a new msg from scratch.
SokiGuo-MSFT 31,826 Reputation points Microsoft External Staff

2023-08-09T09:07:31.5266667+00:00
Hi

Based on your description, this issue seems to be more account-related.

Is it helpful to try to contact the recipient to put you on a safe list?

What is your account type? （Exchange/others）

According to your description, it may be a violation of MTS anti-spam policies, such as using common spam words, links containing malicious or fraudulent websites, low-reputation sender addresses or domains, and email content or formats with a high probability of spamming. If MTS considers the received message to be spam, it rejects it and returns an error message to the sender.

To resolve this issue, you can try the following possible methods to avoid it:

Check if your message contains the above potential information.

Ask your family members to add your email address to their contact list or safe senders list.

Contact the recipient's email provider.

Hope this helps!

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".

Note: Please follow the steps in our [documentation] to enable e-mail notifications if you want to receive the related email notification for this thread.