
Delete the contacts automatically suggested by Mail, Apple’s native messaging system, when composing a new message.
You’ve probably already noticed that when you compose a new message in Mail, iOS automatically suggests the email addresses of contacts with whom you recently spoke.
While these suggestions can be practical to quickly complete the address of a contact not saved in your address book, they can also become problematic when you validate the contact a little too quickly and your email ends up routed to the wrong recipient.
To avoid any misunderstanding, it is possible to manually delete the contacts automatically suggested by Mail.
1. Open a new message
Launch Mail and press the button to compose a new message. In the To: field enter the first letter of the recipient’s address.
All the suggested contacts not in your address book can be recognized by the small i button (for information) associated with them.

2. Delete the suggested contacts
Press the i button on a suggested contact. Mail displays what looks like a contact card, but it isn’t saved on your device. At the bottom of this card, tap Delete from history.

Apple does not offer an option likely to delete all the contacts suggested in Mail at once, you will have to patiently take your trouble and repeat the operation manually as many times as necessary to delete all the contacts suggested by this mail .