Delivered Email Not Arriving
If Mailofly displays the status Delivered (250 2.0.0 OK), this confirms that the recipient’s mail server (e.g. Gmail, Microsoft 365, iCloud) accepted the message over SMTP.
If the recipient claims they cannot find the email, use this troubleshooting checklist:
1. Check Spam / Junk and Promotions Tabs
- Gmail: Check the Spam folder and the Promotions / Updates tabs.
- Outlook / Hotmail: Check the Junk Email folder and the Other tab (under Focused Inbox).
- Search by Sender: Ask the recipient to search their mail client for your exact
fromaddress or message subject.
2. Corporate Firewalls and Email Security Gateways
Corporate domains frequently route incoming mail through third-party security appliances:- Mimecast, Proofpoint, Barracuda, Microsoft Defender
- These gateways acknowledge receipt (
250 OK) to the sending MTA, then hold the message in an administrative quarantine or run background sandbox analysis. - Fix: Have the recipient contact their IT administrator to release the email and whitelist your sending domain.
3. Greylisting and Post-Acceptance Delays
Some mail servers accept mail and temporarily delay final mailbox placement for 5–15 minutes while checking sender reputation.4. Check Message-ID in Receiving Server Logs
Every email dispatched by Mailofly has a uniquemessage_id. Provide this Message-ID to the recipient’s IT department to trace the exact delivery path in their inbound mail server logs.