Present/past Continuous

Hi!

Can I use a sentence like this:

I don't know if you have already sent the official call because our domain has been down for a while.

I'm confused with this second part of the sentence. Can I use two present perfects in the same sentence or do I have to use past perfect in the second part because that had happened before he sent the mail? But the domain stayed non-operational after he had sent the mail, so it is not a common past perfect situation. Maybe I'm unnecessarily complicating xD And is this text ok? Thank you