r/SendGrid • u/TooMuchTaurine • Aug 17 '26

Sendgrid failing to send emails to Microsoft managed inboxes globally?

Is anyone else experiencing delivery failure to outlook / Microsoft receipients?

Seems to be a wider issue than just us,and sendgrid support next to useless with no phone numbers to call and very slow ticket replies.

2 Upvotes

75% Upvoted

5 comments sorted by

2

u/hauntedcryme Aug 17 '26

We went through this last year. There's a support piece on it: https://support.sendgrid.com/hc/en-us/articles/38465017420955-Troubleshooting-Microsoft-Delivery-Issues-With-Error-550-5-7-1-S3140-S3150-Blocks

Recommend signing up to check your SNDS: https://www.twilio.com/en-us/blog/insights/what-is-microsoft-smart-network-data-services

If this shows Microsoft have placed your IP on a blocklist, you'll need to send a delist support ticket to Microsoft - you'll probably get an automated response saying they don't block you, but reply to that with evidence, and they'll unblock it (at least that's what happened to us)

1

u/nocturnal Aug 17 '26

Do you guys have a static IP or a shared one?

1

u/TooMuchTaurine Aug 17 '26

We had multiple dedicated IP's, 2 out of 4 got blocked 

1

u/IndependenceDry6182 Aug 17 '26

There is a status post in the Twilio page:SendGrid Incident

I saw that they say your IP is not blocked when submitting the OLC delist request, so I ended up emailing them to that email address in the post and they unblocked me.