Watch not vibrating with email notifications

Found this, it might be helpful with your issue?

On my previous watch (series 2) I got haptic alerts from email notifications, but when I upgraded to a series 4 I no longer got haptic alerts.

After a bit of digging I found the setting to turn it on (not sure why it was off, must have happened in the update to iOS 12). On your iPhone go to: Notifications -> Mail -> choose your account -> sounds -> vibration

This was set as non (default) for me. Once I changed that I started getting haptic alerts on my watch. You will have to change that for each of your email accounts and make sure your watch email notifications are set up to mirror your iPhone.

Not sure if you already tried that, but solved it for me

Just went into my iPhone and all of my email accounts were set to NONE (default)

wizza2015 wrote:

from what I can see all the usual settings seems to be correct.

And what might those be? (just to confirm)

Is the Watch set to mirror your iPhone's notifications for Mail? If so, check your iPhone's notification settings for Mail, as well as Do Not Disturb.

Or, did you set a custom notification on your Watch which is different from your iPhone's notification settings?

Finally, a common misunderstanding is that you won't get notifications on your Watch if your iPhone is unlocked (the presumption being that you'll get the notification on your iPhone). This is stated in the Watch's settings for Notifications (at the top of the setting).