Unable to Verify the Identity of the Server in Apple Mail

Apple Mail stops with the server identity warning when a mail server shows a certificate that macOS cannot check. Self signed certificates, wrong server names and expired certificates cause it and Mail repeats that warning at every launch until you settle it. Below are Apple's trust steps for a verify server identity error, a hostname fix, a Keychain reset and a backup method to use before you remove an account.

Why does Apple Mail show a server identity warning?

Mail rejects the server certificate when your mail server uses a certificate signed by an unknown authority, like a self signed certificate. Apple's guide states that you can still connect, yet Mail warns you at every launch until you trust that certificate. See Apple's page, If Mail can't verify a server's certificate, for that wording.

Hosting providers explain a second cause of Apple Mail verify server identity errors. Their support pages say a certificate fails when its name does not match your incoming server name. Typical triggers when Mail rejects the server certificate are these.

• A self signed certificate on your mail host.
• An incoming server like mail.yourdomain.com while your certificate names a hosting server.
• An expired certificate on your mail server.
• Network devices that block SSL or TLS traffic.

Cause decides your fix for a verify server identity error so check your certificate before you trust it.

How to fix the server identity warning in Apple Mail?

To fix the server identity warning, select Show Certificate in Mail's warning, check that its server name is yours and tell Mail to always trust it. These steps follow Apple's page, Trust a certificate in Mail.

1. In Mail's Verify Certificate window, select Show Certificate.
2. Check certificate details and confirm that its server name is your mail server. Do not trust a name you do not know.
3. Tick that box so Mail always trusts that certificate. Select Details to see current trust policies.
4. Select Connect or OK.
5. Enter your Mac account password when asked. For a root certificate, Apple says to enter name and password of an administrator on that Mac.
6. Send and receive a test email to confirm that Apple Mail no longer says it cannot verify server identity.

InMotion Hosting adds a detail for self signed certificates. After you select Show Certificate, expand Trust and set Secure Sockets Layer (SSL) and X.509 Basic to Always Trust, then test incoming and outgoing mail. Its guide, Fix Mac Mail verify server identity, shows that order for a Mac Mail verify server identity warning. To adjust trust later, Apple says to open Keychain Access.

How to fix a server name mismatch in Apple Mail?

To fix a mismatch that makes Mail rejects the server certificate, replace your incoming server name with your certificate's name. AccuWebHosting states that errors appear when a certificate does not match your server name in settings and its fix swaps mail.yourdomain.com for a hosting server name. Your host publishes that name so ask support if you do not know it.

1. Open Mail, select Mail in your menu bar, then Settings and Accounts.
2. Select your account, then Server Settings.
3. Enter your host's server name under incoming mail server. Use that same name for outgoing mail.
4. Confirm ports, since wrong ports also make Mail rejects the server certificate. IMAP with SSL uses 993, POP3 with SSL uses 995 and SMTP uses 465 or 587.
5. Save changes and send a test email.

AccuWebHosting's page, Identity cannot be verified by Mail, lists these ports for iPhone and iPad. Mac Mail uses that same server and port logic. Menu names differ by macOS release.

What if Apple Mail asks again to verify server identity?

If Mail still asks, Always Trust did not save for its right policy. One Apple Community thread, Always trust an SSL certificate in Mail, has users who report prompts at every launch even after they tick that trust box. Replies in that thread suggest choosing that SSL option under that box. One user reports success after deleting bad certificates in Keychain Access, adding your root certificate again and choosing Always Trust from Mail's dropdown. That thread closed without a confirmed Apple fix so treat these as user reports.

1. Open Keychain Access and search for your mail server name.
2. Double-click your certificate and expand Trust.
3. Set Secure Sockets Layer (SSL) to Always Trust.
4. Close that window and enter your password to save.
5. Quit and reopen Mail, then check mail.

If Mail rejects the server certificate after that, your mail host must fix its certificate. Hosting guides agree on that last step. Contact your administrator when settings and trust do not clear a verify server identity error. To retain a copy of your IMAP mail meanwhile, see how to Download IMAP emails from a server.

Which fix for the server identity warning is best?

Match your verify server identity fix to its cause. Trust your certificate when you own that server. Update your server name when your certificate names another server. Reset Keychain trust when prompts return. Ask your host when an expired certificate causes that warning.

Can network settings cause a verify server identity error?

Yes. A firewall, proxy or security tool that inspects SSL traffic can swap your server's certificate for its own and Mail then cannot verify server identity. AccuWebHosting lists DNS and blocked SSL or TLS traffic as checks. Test that same Apple Mail account on another network, like a phone hotspot. If your error vanishes, your first network is its cause.

Update macOS if Mail rejects the server certificate on every network, because system updates refresh trusted root certificates. To move mail to another account after you settle that error, see how to Export GoDaddy email to Outlook.

Questions about Apple Mail server identity

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Jared Young

Jared is an engineering graduate in Computer Science who specializes in data recovery and backup. He saves Corbett Software guides on email attachments, backups and mail migration.