Getting error "blocked_outgoing_spam" when using this email to send marketing emails in Lemlist

Question

Hi! We have a few domains we used to send marketing emails to potential customers, I have checked and rechecked them for spam in Lemlist (all green flags), but for some reason, this particular email is having a problem even though I'm sending the same email with other domains to different states and they're working fine. How do I fix? Please and thanks!

---

Moved from Outlook | Web | Outlook.com | Email

Answer 1

Dear @Annie,

The error “blocked_outgoing_spam” is Microsoft’s way of signaling that your account or sending IP has been blocked for suspected spam or bulk email activity. This happens when you use services integrated with an Outlook mailbox to send marketing or cold emails.

First, please confirm if you are blocked and get more details:

• Check the Non-Delivery Report (NDR) if you have one. Look for codes like 550 5.7.501, 550 5.7.502, 550 5.1.8 then take a screenshot and share it with me.
• Go to Microsoft 365 Admin Center > Security > Review > Restricted entities. If listed, the user is blocked from sending.

In the meantime, I kindly recommend restricting outbound email activity by using lower daily sending limits, initially starting with approximately 50 -100 recipients per day. Additionally, please consider making email content more personalized, as this may help reduce patterns commonly associated with automated or spam-related messaging.

Thank you for your patience and understanding. Hope you having a nice day and really much warm regards to you as well.

Looking forward to your response! 

---

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.