Some people break up and never speak again; others weirdly impressively become best friends. Most people, however, fall somewhere in between, and sadly it’s when you’re somewhere in between that it’s the most difficult to figure out how to act.

A really important thing to remember when dealing with an ex is that there’s always the possibility that you make them sad. Or, if not sad, a little bit nostalgic. And in the age of smartphones, people are connected 24/7: if you send your ex a long, angsty email while they’re celebrating their birthday, or about to take an important test, or at the hospital with a sick family member, they will get it and read it right away. So really think about what you’re saying, why you’re saying it, and how this is going to make your ex feel. If the answer is anything other than “happy that I reached out!”, consider holding off.

Here are some basic guidelines — not hard and fast rules, but recommendations for when to reach out and when to stay quiet.

When It’s NOT Ok

When you’re drunk

When you’re lonely

When they first start seeing someone and seem happy

When you first start seeing someone and want to flaunt it

When you’re going through a breakup with someone else

When it’s their birthday (apart from the briefest “Happy birthday” Facebook message or text)

When it’s their wedding day

When it’s 1 am on a Saturday night and you just want to know what they’re “up to”

When you see a book/picture/commercial/blade of grass that reminds you of an inside joke, and you just wanted to share it with them. (And this happens every week.)

On what would have been your anniversary

When you want to tell them they look hot in a recent Facebook picture

When it IS Ok

When they get a new job/exciting career development

When they have a baby

When they get engaged (but only to congratulate! No “WHYYYYYYYY?!”s allowed.)

When a parent or loved one dies (yours or theirs)

When something amazing and gossipy happens and you just know they’d love to hear about it, AND this isn’t the first post break-up contact you’ve had.

When you haven’t talked in a while and just want to check in (infrequently)

And as for modes of communication…

A Text is okay on birthdays.

A Facebook Message is also ok on birthdays, or after long periods of no communication.

An email is the best form of communication for whenever you’re in doubt.

A letter is ok if you’re a time traveler or if they’ve taken out a restraining order and blocked your number.

A phone call is best after someone dies, especially if you knew the person well. But if they don’t pick up, don’t call back — email your condolences or send a card.