I have this vague recollection of this manga I once read. I'm pretty sure it was yaoi/ shounen ai but there is a slim chance it was shoujo, very slim.

Anyways, what I remember is that is was pretty generic. The only thing that is really clear to me is that they were friends and one moved away. When he came back/they met again they weren't close anymore. (very generic...) I just remember that they both did try to keep in contact but the mail and what not never was received on either end.

I think it was set during highschool. I've been looking for it but none of the 'childhood friends reunite and become lovers' manga that I've checked has that part where they contact failed to go though. Usually one was mad/to lazy and didn't contact the other.

Other then that, I don't even know if it was good or bad... I just forgot it. I want to know what it is just to know really.

Well this description kinda reminds me of Kagami wa Iranai (I don't need a mirror!) from Koisuru Cupid. Although it's about cousins, the rest (i mean -being childchood playmates, separation, misundersanding due to problems with letters, not getting allong after being reunited) fits quite well. There's also Tenohira no seiza, which is pretty similar

It was Kagami wa Iranai, thank you!

I had also thought it was Tenohira no seiza too. I think I read it 3 or 4 times because I kept looking for Kagami wa Iranai.