I have mailed you or i mailed you

A classic example of a grammatical conundrum!

Both "I have mailed you" and "I mailed you" are grammatically correct, but they convey slightly different meanings.

"I have mailed you" is in the present perfect tense, which implies that the action of mailing was completed at an unspecified time in the past, and its effects still continue up to the present moment. For example:

"I have mailed you the package, so you should receive it soon."

"I mailed you" is in the simple past tense, which describes a completed action in the past without specifying when it was completed. For example:

"I mailed you the package yesterday."

So, if you want to emphasize that the mailing occurred at a specific point in the past, use "I mailed you". If you want to emphasize that the mailing occurred at an unspecified time in the past, and its effects still continue, use "I have mailed you".