No matter how long you haven’t contacted us, what do we mean?

No matter how long you haven’t contacted us, we still mean that “the feelings have not changed over time and can withstand the test”.

This sentence describes the sincere and deep feelings. Even if friends have not seen each other for a long time, the feelings will not change.

Similar sentences include "The most beautiful form of friendship is that we haven't seen each other for many years and still remain the same. The green years are precious memories."