Yes. This can happen with Outlook.com even when no rules are configured and the sender is on the Safe senders list.
The supported causes in this scenario are:
- Server-side filtering can block some messages before they reach the mailbox. Safe senders and rules do not always help if the message is filtered or rejected earlier in the delivery path.
- Some verification emails are delayed or not delivered because of sender-side authentication problems such as SPF-related failures. In that case, the sender must fix their mail configuration.
- Outlook.com account conditions can also affect delivery, including:
- full Microsoft cloud storage or mailbox storage
- temporary account blocks caused by unusual sign-in activity
- forwarding enabled unexpectedly
- junk email settings or Focused/Other tab placement
For the checks that are available in Outlook.com, use this path:
- In Outlook.com, check Junk Email, Other, and message sorting.
- Go to Settings > Mail > Forwarding and confirm forwarding is off unless intended.
- Go to Settings > Mail > Rules and confirm no rule is moving or deleting mail.
- Go to Settings > Mail > Junk email and review Safe senders and domains and blocked senders.
- Check whether Microsoft cloud storage is full, because if storage is full, Outlook.com cannot send or receive email and messages sent during that time are bounced back and unrecoverable.
- Check whether the account is temporarily blocked due to unusual sign-in activity.
For verification-code emails specifically, also check:
- the correct mailbox or alias is being used
- Junk Email for messages from
@accountprotection.microsoft.com when the code is from Microsoft
- repeated code requests are avoided, because excessive requests can temporarily stop code delivery
If the problem happens only with certain websites like Steam and normal mail still arrives, that is consistent with either sender-side authentication issues or Outlook.com server-side filtering of those transactional messages.