Is Your Apple Mail Broken On iOS 18.5? Here’s A Quick Fix
While there has not been an official response from Apple just yet, users have found the following suggestions helpful.
Fix 1: Simply reboot your iPhone and open the app again. To do this, long-press your power button and your volume down button together. Thereafter, swipe the power button to the right. After your iPhone is off, turn it on with the power button. Alternatively, quick press the volume up button, quick press the volume down button, and then long-press the power button until you see the Apple logo on the screen.
Fix 2: Reset your iPhone's network. To do this, open your settings app and tap General > Transfer or reset iPhone > Reset. Thereafter, select reset network settings, input passcode, and follow onscreen instructions to complete the process.
Fix 3: Disable keyboard settings like auto-capitalization and smart punctuation. To do this, open your Settings app and tap General > Keyboard. Then, toggle off auto-capitalization and smart punctuation.

Fix 4: You could also close and reopen your iPhone Mail app.
We hope at least one of these fixes works for you. Reports of the Mail app crashing after updating the app or OS are quite common. A few weeks ago, we reported that several Outlook app users complained that the app was crashing after an update. These issues are usually addressed officially, however, in the absence of an official fix, users can try some simple workarounds, which are sometimes effective.