Email delivery problems usually come down to one of a small number of causes. Checking these first often resolves the issue faster than waiting on a support ticket — but if none of them apply, we treat email issues as high priority regardless.
Mail not sending
- Mailbox full — if you're at or near your storage quota, outgoing mail can be blocked entirely. Check your mailbox's storage usage in the client portal or your mail app's account settings.
- Incorrect outgoing server settings — a wrong port or security setting for the outgoing (SMTP) server is a common cause, particularly after switching networks (some networks, especially mobile hotspots, block the standard SMTP port).
- Attachment size — most mailboxes have a per-message size limit. If a specific email with a large attachment fails while others send fine, that's usually the cause.
Mail not arriving
- Check spam/junk first — this sounds obvious, but it's the most common actual cause, particularly for mail from a new sender your recipient hasn't emailed before.
- DNS records — if this started after a domain or hosting change, your MX records may not be pointing to the correct mail server. See Understanding DNS Records for how this works.
- Recipient's spam filter is rejecting your domain — if your domain is missing SPF or DKIM records (both are TXT records), some mail providers will reject or spam-flag your outgoing mail as unauthenticated. This is increasingly strict — since 2024, Gmail and Yahoo actively enforce this for any domain sending meaningful volume.
If it's affecting everyone on your domain
A domain-wide email outage (nobody can send or receive) is different from a single mailbox issue and usually points to a server-side or DNS problem rather than something on your end. Submit an urgent ticket and mark it "Critical" — these are treated as high priority.
Submitting a ticket for an email issue
Include the affected email address, whether it's sending, receiving, or both, and any exact error message you're seeing — the wording of a bounce-back or error message usually tells us exactly what's wrong before we even start investigating.