How should I approach asking a contact on our email marketing list, who has previously unsubscribed from emails regarding a show, to resubscribe now that a new show is planned?
We run numerous exhibitions, which happen yearly. We're looking to implement a new preference system shortly where someone can not only unsubscribe from every email regarding that show, but has the option to only unsubscribe from this year's marketing. This is useful for people who have already stated they are attending/exhibiting at the show, and do not need any further marketing, but want it to resume next year.
The only problem is, we've been running shows (and performing email marketing) for well over ten years, and this preference centre is only being implemented now. We have millions of contacts on our lists, with thousands of unsubscribes, and the-powers-that-be want to ensure that people who previously unsubscribed actually wanted to.
Now, I know it's very close to the legal line doing this, but I want to ensure that we stay on the correct side of it. Can we simply send an email saying "We're sorry you left... would you like to come back?" or would something else be needed? As we have numerous shows, and a contact could well have unsubscribed from many of them, am I allowed to send them the email for each show? Or can I only email each address on file once? Can I send a similar email every year to unsubscribes, who may have checked the wrong box in the preference centre last year?
On a more design-orientated side, (seeing as this question will be posed to designers): if I was able to do this, how should I word/design the email? Should I be very sheepish, with numerous apologies for the possibly-intrusive email, or be bold and assume that they will want the email, effectively trying to convince them that this is definitely a good (but one-off) thing?