Mail is very slow downloading in iOS 18

Ok, I have some new data: The Apple mail app works fine on my neighbor's WiFi and on AT&T 5G (both raw internet) - but NOT my home nor work WiFi. Apparently, the mail app has an issue with my pfSense router - specifically the pfBlockerNG firewall on it - and the work WiFi obviously washes through an enterprise level firewall (Cisco Layer 3) the app also has an issue with. At home, I can shut off the pfBlockerNG firewall and the mail app works just fine.

Funny thing is, the firewall is not returning errors nor alerts. The Layer 3 Cisco at work isn't either. I tried allowing all 17.x.x.x in both directions through the firewall, no dice. But, if I shut off pfBlockerNG, it works just fine. Ironically, it appears to work with Snort if you allow 17.x.x.x, but not pfBlockerNG. Obviously, I am not shutting off my firewall and risking letting the barbarians through the gate!

After contacting Netgate and Cisco, they did some testing and it appears the issue is on APPLE's side! Apparently, something on Apple's servers is trying to handshake through the firewalls and it is being dropped. However, none of us can see what exactly it is. Judging by the responses on here, other corporate/business firewalls also have the same issue. However, because it is on their side alone, no alerts are triggered on the end user's side so the IT folks (like me) can allow the mail app to filter through.

Apple better get their heads out of their apps and fix this - and FAST, lest they want to lose so many corporate customers. Our C-suite execs are already asking how involved switching to Droids will be. Yikes!!

Same here on both MacOS 15.2 and IOS 18.2. Have tried deleting accounts and recreating, rebuilding inboxes and still unreliable at downloading new messages. Sometimes instant but most of the time takes hours or days to see new emails. Tried email prefix changes, Email privacy disabled etc. Same accounts work fine in other mail clients so having to use those for now.

I'll state this again. I had the same "stuck" mail issues using the native IOS mail app, under IOS 18.1. What I did to remedy was:

1) Delete the affected Mail Account(s) via "Settings -> Apps -> Mail -> Mail Accounts". Select the offending mail account, and then "Delete Account". Repeat for all offending mail accounts;

2) Restart your iPhone;

3) Re-establish your deleted Mail Account(s) via the sequence above, and select "Add Account" to re-establish each individual mail account;

This was the only thing that worked for me, and I did it a couple of months ago under the auspices of IOS 18.1, have updated to the latest IOS (18.2.1) since, and it's still running fine without any issues.

FYI, unlike some other users have noted, I did NOT have to fiddle with any firewall filters to get this back working.

Is there anything we can do other than comment on these boards. This is ruining my workflow

I'm typing this as I just waited 10 minutes for a very short email to download in Apple Mail with my icloud.com account on my new iPhone 16 Pro with iOS 18.2 with good wifi. I have been intermittently, but more often then not, having this problem ever since I bought the phone. Also having this problem on my iPhone 14 Pro ever since upgrading to iOS 18.0. This is incredibly frustrating. I will have to think twice about updating in the future. I am using a gmail, icloud, and custom imap account in mail and they are all experiencing the same issue.

Dear Apple, Please fix ASAP!!

UPDATE: Looks like the iOS 18.3 update solved the mail issue for me as well as the vast majority of other iPhone users in the company that utilize the native Apple mail app.

Same here: very slow downloads on my iPad since updated to iOS 18.

However, it is lightning fast on my brand new iPhone 15, running iOS 18.

Strange isn’t it? It’s almost like upgrades are designed to make your existing equipment perform poorly so you will buy new equipment. Hmmmm.

Mail is very slow to download on my iPad mini and iPhone with iOS 18.1

I agree the mail load is very slow you need a calendar to time it

My main account is an iCloud.com one and it’s really slow to connect so not just a gmail issue.

I’m having the same issue with lots of time spent in the “Connecting…” phase after updating to iOS 18.1.1 on my iPhone 15 Pro. The proposed solution here unfortunately did not help, even after a phone restart.

Maybe it’s just me, I’m experiencing slow mail on all my Apple devices running the latest IOS (18) or OS. With no success I’ve tried deleting and adding back my email account (not Gmail), and updated the email account settings (adding the “/“). This problem, that others have reported here with slow email continues.

As said here and elsewhere more than once - Apple needs to acknowledge the problem exists and come up with an actionable solution ASAP. Please

There appear to be multiple causes for this issue. I tried many of the suggestions in this thread, but none worked for me.

In my case, I found that if I disabled wifi and used cellular that everything works as expected. So the issue for me pointed to my router. There is a feature on the router whose purpose is to block user-select-able categories of websites - primarily used for parental controls. After much experimentation, I found that the mail app functioned normally if I disabled this feature on the router. I'm ok with that for now because I use a DNS service to provide much the same filtering to block categories of websites.

So, for those of you who haven't yet been able to resolve the mail issues and if the problem exists on wifi but works with cellular, then you should check to see if your router has some sort of website filtering controls for blocking 'undesirable' websites.

Thanks! This fixed it for me

My emails are slow to download since the latest update