[Veespin]

The first can also mean "I want friends where we can send letters to each other."

The ～合う suffix added to some verbs means "each other."

Examples:
言い合う（いいあう）＝to argue (lit. talk to each other)
(Note: This is NOT the same as 話し合う though.)

絡み合う（からみあう）＝to intertangle, to entwine with

連絡し合う（らんらくしあう）＝to communicate with each other

The あえる form of the verb means "to be able to".

Keep up the good work, man. I hope everything works out for you.