Friendship is a two-way situation. To have a strong friendship, there is a giving, and receiving, a sharing on both sides. If one person is giving much more than the others the friendship will have difficulties, so we need a balance. If you find that your friends are not reciprocating as well as you would like them to, then you've got two choices. One is to accept that level of friendship and lower your expectations. Also, in this particular case lower the amount of emails you send to them because they are not interested in that form of communication on the same regularity as you want. So you can lower it to their level and keep the friendship. Or you can decide that this friendship isn't what you want, this person is taking too much and not giving back a similar amount. It's a question to consider for a lot of people who get really caught up in the world. They might have a scattered mind and they just can't organize themselves enough to write emails back to people. To a certain degree they still care but they're not really making the effort to show their caring. Those sort of people do lose friends because it's hard to keep friends by only taking and not giving in return.
I've got two friends from high school that I stay in touch with on a fairly regular basis. For one of them it's one phone call a year. Whenever I'm back in America I give them a call. They live in a different town to my parents. We have a nice chat for 20 minutes or something, that's it. Sometimes there's a New Years' greetings that goes back and forth, that's it. And that's a level that the other person really wanted, and I felt, it's all right, you know, we're half way around the world from each other, we don't really share a great deal, although they do have an interest in Buddhism.
The other friend from high school I see every year because he still lives close to my parents. We usually have dinner together. And we will write two emails a year perhaps, about two sentences long. Those friendships have stayed on those levels and we are still friends. I feel that if I was totally wiped out, down to my last Euro, and I needed somebody to help me out, I feel I could knock on their door. I may not really like to stay with them very long, but I feel that they would give me some help. So that's the kind of friendship level I've accepted for these people.
If you can lower your expectations on some of the people whom in this particular case hardly ever reply, then you might keep that friendship. Drop your expectations and maybe you don't have any problem. But hopefully you're going to find that you will have other friends who will reply regularly, and that's where we're going to make a stronger commitment.