by jamesd » Thu Jan 28, 2016 7:15 am
Past answers to this request have been simple: "no, it would use too much in the way of resources because forwarding is much more work than eating". The system relies on eating most emails and over time you will probably find that enough addresses get abused so that yours will tend in this direction as well.
To do what you want, use trusted senders, not exclusive senders. With a trusted sender the email will still reach you if they send from a different address, either with no use of the count if they use the same domain, or a use of one per email if they have switched sending domain to one that is not trusted. That gives you time to notice and add a new trusted sender if you want the emails.
Exclusive senders have uses but compared to trusted senders they are a way to shoot yourself in the foot. If you really do want to do it with exclusive senders be sure to turn on the option to log details of the last three eaten emails because it will be your main way of discovering that you're missing emails because the sender has changed. Best to use the option not to log hidden addresses because those will be the ones that have spammed you and you won't care about them. The last entry in my log is from about three months ago from when I needed to add a new trusted sender for a source.
After 14 years here I've accumulated some 80 trusted senders but more than 600 disposable addresses with about fifteen times as many emails eaten as forwarded.
The normal counts are a pretty capable tool for places where you only occasionally if ever get email and it's not hard to look at all email addresses, click on the remaining count title to find those with few remaining and update where desired or add a trusted or exclusive sender. You can also add email rules to highlight messages when the count is reaching the limit or when last one! appears, then visit the site to update or decide that yes, this one really does deserve a trusted sender.