If you are getting a message in AltaMail about contact access, then you need to check your device access settings.

Open the Apple iPad/iPhone "Settings" app > Privacy > Contacts > AltaMail. Check that AltaMail is set to "on".

Also tap into the Settings app > Apps (near the bottom). Tap on AltaMail and then tap "Contacts" to choose Full Access or Limited (or just turn on the switch).

If you do not want to use contacts at all, you can open the App Settings in AltaMail. Then open the Application section and turn off 'Ask for access to contacts'.