iPhone cannot verify server identity

I had this Same Problem and what I kept doing was Deleting email and then adding back, but that didn't fix

So after a lot of trouble shooting this was what Solved it so I could get the Continue to be able to Trust Certificate

1st Delete the Email Account that's giving you Trouble

2nd Go back to Settings and then Mail then Click on Accounts then click on another email account that you have on there click on it then Outgoing Mail Server

After getting to the Outgoing Mail Server Click on the Email that you deleted in 1st step then Scoll down and

Delete the Server!

3rd and Last Re Add Email Account and the Contiue will pop up to Verify Server

If you need help feel free to message me

Today, I ran into the same issue with a co-worker of mine.

Somehow he couldn't setup his mail account on his iPhone, while it is running without any issues on mine.

On my iPhone i could select the Trust certificate option while creating the new Exchange account, while the Trust-option wasn't available on his phone.

At first I thought it might be the iOS version (10.2.1 vs 10.3), but I have the account running on my iPhone for over a year already.

The other difference was the WiFi being used: WEP-security on his phone and WPA2 security on mine.

After adding the SSID with WPA2 on his phone, and recreating the account, suddenly the Trust option was there as well.

This is confirmed in Certificate "Not Trusted" on iPhone.

Now it's running like a charm

genius2016 has the solution here, at least until Apple notice and do something about it.

contoso.com below is a made up MS test name used in examples.

The underlying problem in our case is our Exchange server is https://mail.contoso.com and a first connection to our exchange will go to https://mail.contoso.com/autodiscover. Our server only has contoso.com, not mail.contoso.com on its list of accepted names, so the phone doubts the server. As explained ios users used to have an override button for this so we could look at the cert and determine it is ours actually, just missing the autodiscover name so we can accept it.

This has indeed disappeared in recent ios releases.

In my case Exchange 2010, I needed to enter my domain but it went through after that no problem.

I would recommend the unchecking your SSL option since your email will then be travelling enencrypted over the internet for all hackers to see.

Great fix genius2016, thanks for saving me a lot more time!

I have been using IMAP for years, the only time I EVER have problems is with iOS / MacOS and how it handles SSL certificates. I have their flagship iPhone 7 Plus 256gb, it's a work phone and effectively useless due to this BUG.

It's a new year so my ISP issues new certificates, fine on MacOS I just tell it to trust them, but on iOS I have no control. All I can do is press "cancel" when the pop up (spam?) warning message appears, and wait 2 seconds for the same message, cancel > popup > cancel > popup. I can't quit mail, launch springboards or do anything else when this loop happens. My only option was to turn off the phone and delete the account.

"Mail cannot verify server identity" endless cancel / popup loop made me restart my phone three times today and stopped me using my company email. If this was not Apples doing I would call it Malware. It's not funny, it's pathetic.

You want to be taken seriously for business applications? Fix this.

If you're able to receive but not send mail, I can confirm that this is all related to a bug in the SMTP server settings stored on the device. Someone else mentioned a version of this solution earlier, but here's a step-by-step guide to how I finally cleared it up after a day of dangerously high blood pressure:

If you have more than one mail account, skip to step 2.

1. Only applicable if you have one mail account on your phone: Create a bogus mail account with fake settings. Just get it to be saved as a legit-looking account, and you should be OK.
2. Delete the problematic account.
3. In any other mail account, find where all your SMTP servers are listed (Account > SMTP).
4. The one from the problematic account should still be there. Tap on it to get the details, and hit Delete Server.
5. Make sure you don't have multiple listings for it. If you do, delete those, too.
6. Re-add the account you deleted. You should finally get the full Cannot Verify Server Identity dialog with Continue, Details, and Cancel.
7. Assuming you need to trust the certificate, hit Details. You should see the Trust option. Tap it!
8. You may need to repeat step 7 to cover both incoming and outgoing servers.
9. If you created a bogus account in step 1, be sure to delete it or Mail will get stuck on trying to get it to work.

This worked for me. I hope it works for you if you have the same problem I did.

This is a solution for EXCHANGE accounts as of 2017.07.31, iOS 10.3.3.

You won't sacrifice your SSL. I am detailing genius2016's suggestion.

First, when using EXCHANGE accounts, iOS requires 4 things to register your account:

1. Email address: name.lastname@domain.com
2. Email password: 123456789
3. EXCHANGE user name: nlastname
4. Server (EXCHANGE IP): 000.000.000.00

You should now that regular registration process follows 3 screens or steps:

1. Checking if the service is available or exists
2. Checking your EXCHANGE account
3. Registering your email

Step A, you should employ your EXCHANGE account name (not an email account) to register (your email and user name could either be identical or different, check with your network administrator):

Instead of typing your email:

"name.lastname@domain.com"

Type your "user name" followed by "@" and your "IP" and proceed:

"nlastname@000.000.000.00"

On Step B, you employ the exchange user name ("nlastname@000.000.000.00") & your password.

This will give you an error message, "cannot verify server identity". Click on details, and you will see a new option on the upper right corner, "TRUST". Press that option, and your system will validate and accept the certificate. Then you can continue.

This will take you to the step C: You will enter your data as required (email in the email field, password on the password field, etc.).

My best regards.

-SQR

I meant to add that another forum post (couldn't find it again) pointed me in this direction and also mentioned these two references: Lists of available trusted root certificates in macOS - Apple Support and https://blog.mozilla.org/security/2016/10/24/distrusting-new-wosign-and-startcom -certificates/

We had the same error message after the certificate on our mail server changed to a different name. We have no control over the server as our domain is just one of the many accounts hosted on that server. I tried various fixes to no avail. The problem was resolved by going to Settings -> Mail -> Selecting Email Account -> Turn Of SSL.

This might help some other users.

This is an Apple issue that started for me when I did update to 10.2 last night. Now I cannot access my exchange mail on iPhone or IPad. We have a small business with a "self issued" security certificate.

I get same warning as original poster with no ability to bypass. I can bypass in Safari but that does not help with e-mail.

Same issue. I have a hosting account at bluehost.com. There certificate is *.bluehost.com which is fine with me as I know it is them. But my email is my domain. So Apple, the only problem I have is that you broke my email... completely on the iPhone. And it has not been broken for months. Did you mean to drive me to gmail for mail? Because that's what you are doing.

After upgrading to 10.2.1 our customers started having issues with SSL/TLS connections to our servers.

The above suggestions did not work for us. Scouring our server's mail log didn't help much; just saw the TLS disconnect in the log issued by the client.

Our certificate was created at StartSSL (StarCom), and it appears that StarCom root authority will no longer (or is no longer) supported by 10.2.1. Once we purchased a certificate elsewhere and installed it, the iPhone had no issues validating and connecting via TLS. (imap SSL port 143, smtp SSL port 587).

I should mention that Android, Thunderbird and Outlook 2010/2013 did not have issues with our certificate, nor did iOS 10.1.n. Any websites using certificates created at StarCom also worked fine (including Safari).

Well, I hope this helps someone else.

Well, I solved the problem -- I forked-over the money for a commercial certificate.

An uneccessary added cost for a small business, but it has the advantage of also working for migrating our web server to SSL...

Indeed, the only way two times in a row to make my mail live again – to remove mailbox from iOS. Then go to smtp severs in Outgoing Mail and remove that old smtp server, that have left after mailbox deletion. Especially easy it is if you have some deferent mailboxes.

You may reboot after it.

Then set up your box again.

It worked well for few people.

This is definitely a problem with iOS 10 and the iPhone 7.

I have the exact same email accounts on both my iPhone and my iPad. Both run the same version of iOS 10.2.1.

When my email certificates were updated by my email service (Dreamhost), I got the same untrusted error on both devices.

Under Details on my iPad, the Trust button appeared and worked fine.

Under Details on my iPhone, the Trust button is missing.

It appears that Apple forgot to include the Trust button on the iPhone.

Please Advise.

I had this Same Problem and what I kept doing was Deleting email and then adding back, but that didn't fix

So after a lot of trouble shooting this was what Solved it so I could get the Continue to be able to Trust Certificate

1st Delete the Email Account that's giving you Trouble

2nd Go back to Settings and then Mail then Click on Accounts then click on another email account that you have on there click on it then Outgoing Mail Server

After getting to the Outgoing Mail Server Click on the Email that you deleted in 1st step then Scoll down and

Delete the Server!

3rd and Last Re Add Email Account and the Contiue will pop up to Verify Server

If you need help feel free to message me