Grammar[tenses], sentence correction

Hello,
Which one is correct?

I email/will email you for the confirmation/to confirm that/after/when/if I received/ have received the letter.
or
I send/will send an email to you for the confirmation/to confirm that/after/when/if i received/ have received the letter.

Context: I was expecting a business letter from XZYcompany. But it's never arrived. After a while i emailed the company that i haven't received the letter and there must have been some mistake. I've sent them my contact information again to make sure that they will send the letter where they're supposed to withou any mistake. I was going to email the company, as soon as i receive the letter, to avoid any further delay. So we could continue our collaboration.

So I was thinking, what sentences i would use to make sure it's correct and understndable. : I email you to confirm that I have received the letter...... Is this correct english and would the native speaker talk like this in this situation or not?
After you tell me your idea about what the native speaker would most likely use for this situation. Would you bother to explain and in what occasions you would use different tenses and explain why or why not is possible to use that/after/if/when

Here are some of my ideas pls do check the meaning and let me know if i get at least anything about right. that/after/when/if:
After- After i received the letter, I email you to let you know. And make sure we can proceed with building up our business relationship. I'll email you After i received the letter. It feels like it's not correct.
using "if" - If i get it right I can use 'if' for situations like these: If i receive the letter I will email you about it. What i think it means: I have doubts. There is a chance, I won't receive the letter. - based on previous expierence with this company : It happened once so it could happen again. It's not certain the letter arrives. So i use If cuz it's not certain. Also It means I email the company only in case I receive the letter.[No letter = no email] am i correct or not?
using when - I can use "when" instead of "if" - It means i have no doubts and it's more certain that the future context will happen.

Email/Send an email i guess both are correct but i wanna know what you'd prefere Email over send an email or on the contrary and why?

Thanks for help ^.^