Check MX records, mailbox settings, quotas and delivery errors before changing email DNS.
Start with the checks below. Each step explains what to look for and what to try next.
Confirm where the mailbox lives
Identify whether your domain uses cPanel email, Google Workspace or another provider. That determines which MX records should be published. Adding both providers’ MX records accidentally can misroute mail.
Trace the email delivery path
Trace the email delivery path
Confirm mailbox existence, aliases, filters and quota.
Review MX records and the selected mail service provider.
Read the SMTP error code; it often identifies rejection or routing problems.
Confirm that DNS changes did not replace existing mail records.
Before you continue: Changing MX records can interrupt business email. Take a copy of your existing records first.
Inspect the domain’s mail route
- Review the authoritative MX records and ensure they match the intended service.
- Check whether the mailbox exists and has available storage.
- Review spam or quarantine folders and any forwarding rules.
- Send a test from another provider and note any bounce message.
Interpret common errors
“Mailbox full” points to quota, “domain not found” suggests DNS, and “user unknown” may mean the recipient address does not exist. Some failures happen at the sender’s server and need the complete bounce details.
Avoid accidental outage
Do not replace MX records until you know which provider handles your mail. Changing DNS for the website does not require changing MX records.
How to confirm the issue is resolved
- Repeat the original action that produced the issue.
- Check the result in a second browser or network when relevant.
- Review logs or status messages for remaining errors.
- Keep a short record of what changed so it can be reversed if necessary.
If the issue persists, contact support with the exact error, time, affected domain and actions already tried—never include passwords or secret keys.
A safe email-delivery test
Send one message from an external mailbox and record its time, sender, recipient and any bounce message. Check the receiving mailbox through webmail as well as the email application. This distinguishes an account/client problem from delivery problems.
- Webmail receives it but the phone does not: Review the email app settings and synchronization.
- No delivery and a bounce is returned: Read the error code before modifying MX records.
- No bounce and no inbox message: Check spam filtering and the domain's authoritative MX records; allow for recent DNS changes.
If you use Google Workspace, follow the Google Workspace domain setup guide. Avoid adding both Google Workspace and cPanel MX destinations without a deliberate mail-routing plan.
Guidance may vary by plan, control panel version and enabled features. Review the settings available to your account before changing live services.