GoDaddy Email Email Verification

What the MX records tell you

GoDaddy hosted mail domains publish MX records pointing at GoDaddy's own infrastructure, most commonly smtp.secureserver.net paired with mailstore1.secureserver.net. Mailthentic matches the secureserver.net family and identifies the domain as GoDaddy. It is worth knowing that a domain registered at GoDaddy does not necessarily use GoDaddy for mail. Many GoDaddy customers were migrated to Microsoft 365 through GoDaddy's reseller programme, and those domains publish Microsoft MX records instead. In that case the domain is handled as Microsoft 365, not as GoDaddy, because the MX record is what decides which platform your probe actually talks to.

How GoDaddy answers an SMTP probe

Verification opens an SMTP session to the GoDaddy host, issues EHLO, uses a null sender, and issues RCPT TO for the address under test, then closes the connection. DATA is never sent and no message is delivered.

On a GoDaddy domain that has not enabled catch-all, a nonexistent mailbox is rejected with a 550 and Mailthentic reports the address as invalid. That much is reliable. The problem is how many GoDaddy domains do have catch-all enabled, whether the owner chose it, inherited it from a default, or configured a forwarding rule years ago and forgot. On those domains the server accepts RCPT TO for absolutely any local part, real or not, and returns a 250.

Why catch-all destroys mailbox confirmation

Catch-all means the domain has been told to accept anything addressed to it rather than reject unknown recipients. Mail to a genuine mailbox goes to that mailbox. Mail to an address that does not exist goes to a designated bin or forwarder instead of bouncing. The consequence for verification is absolute: since the server says yes to everything, its yes carries no information about any specific address.

Mailthentic detects this directly. Alongside the probe for the real address, it probes the domain with a randomly generated local part that could not plausibly belong to anyone. If the server accepts that too, the domain is catch-all. Mailthentic then reports the address as accept-all or ambiguous rather than valid, because claiming otherwise would be a fabrication. No SMTP based tool, from any vendor, can confirm an individual mailbox on a catch-all domain. Anything that claims to is inferring, not verifying.

This is the single biggest reason so many small business domains come back as accept-all in a list. It is not that the addresses are bad. It is that shared hosting platforms like GoDaddy make catch-all easy to turn on and often leave it on, and the platform then loses the ability to tell you anything specific.

Rate limiting and greylisting

GoDaddy runs shared infrastructure serving a very large number of domains, and it protects that infrastructure with connection limits and throttling. Probing too many GoDaddy domains too quickly will produce temporary responses such as 421, 450 or 451. These are deferrals, not rejections, and treating them as invalid addresses would be a serious error. Mailthentic classifies them as temporary and retries on a backoff. It also throttles by MX host cluster rather than by domain, so a list containing two hundred different GoDaddy customer domains is paced against the shared secureserver.net infrastructure as a single target rather than opening two hundred simultaneous connections to the same servers.

What a result here genuinely means

An invalid verdict on a GoDaddy domain means the server rejected the recipient and the mailbox does not exist. A valid verdict on a non catch-all GoDaddy domain is meaningful. An accept-all verdict means exactly what it says: the domain accepts everything, and the address is unproven. That is the honest answer, and it is the one you should build your sending strategy around.

Accept-all is not a synonym for bad

The single most common mistake with GoDaddy domains is deleting every accept-all address. Most of those addresses belong to real small businesses with real mailboxes. The verdict is telling you the server would not confirm the mailbox, not that the mailbox is missing. Deleting them wholesale throws away good contacts. Sending to them blindly risks bounces. The right move is to segment and treat them as their own risk tier.

Rank accept-all addresses with the evidence you have

• Engagement. If the contact has opened or clicked recently, mail them. Real activity outranks any SMTP handshake.
• Source. An address from your own signup form is far safer than a scraped or purchased one, whatever the verdict says.
• Plausibility. A first name at a small business domain is credible. A generic pattern that looks machine generated is not.
• Role prefixes. On small business domains, info and sales and contact addresses are extremely common and usually real, but they are shared inboxes. They deliver, and they drag engagement metrics down, so keep them out of cold outreach.

Send in stages

Do not put an untested accept-all segment into a large campaign. Send a small batch, measure the bounce rate for that segment on its own, and let real delivery do the job SMTP could not. On a catch-all domain the unknown addresses may not bounce at all, since the server quietly swallows them, so watch engagement as well as bounces. A segment with a plausible bounce rate but near zero opens is a segment full of addresses landing in a catch-all bin.

Protect deliverability

• Authenticate with SPF, DKIM and DMARC before you send anything to shared hosting platforms.
• Warm new sending domains and IPs gradually. Small business mail servers and their upstream filters are unforgiving of sudden volume from an unknown source.
• Respect deferrals. A 421 or 451 from GoDaddy means slow down, and continuing to push will hurt your reputation.
• Keep complaint rates low and make unsubscribing trivially easy.

Suppress what you can prove

Anything Mailthentic marks invalid on a GoDaddy domain was hard rejected, so suppress it permanently. Suppress anything that bounces on a live send. Re-verify accept-all segments on a schedule, because small businesses close, staff leave, and a domain that was accept-all last year may not even resolve today.