We have a policy at work not to auto collect email addresses to prevent the autocomplete/user to make the mistake of sending the email to johndoe@thenewyorktimes.com instead of johndoe@client.com.
We fill the address book with only internal addresses so mistakes stay within the company.

So the only way we are allowed to use airmail is if we can prevent the collection of addresses.
Please make it an option which we can disable.