[kvakerok]

You can simply put two buttons on the email, one for unsubscribe, one for re-subscribe. If they unsub by accident they can simply pull the last email and re-sub. It's not rocket science.

[rbut]

AFAIK Google shows you an unsubscribe button/link separate to the email and performs the POST request to your server. There's no option to ask Gmail to show a resubscribe button/link.

[wredue]

Or, send an email saying

“Hey. You unsubscribed. Here’s a link to resubscribe if you happen to want to!”

Right after someone unsubs.

[albertgoeswoof]

You could also send them a reminder a few days later, just to be sure that they meant it. And then perhaps every week or so for good measure.

[reaperman]

And you could probably take the time to add your weekly special deals to that reminder email, in case they might see something they like or need.

[janosdebugs]

That seems to be a bad idea. The new rules state that you need to process the unsubscription within 2 days. Sending an email a few days later sounds like a good way to make it on the naughty list.

[account42]

Don't be absurd - those rules are for evil spammers, not for your marketing department.

[wredue]

There’s a far cry difference giving someone a subscription link at unsub time and spamming resub links.

It’s already pretty standard practice to send an email notifying that the unsub request was processed.