can I synchronize my emails on one gmail account via IMAP?
 

I have one email @myowndomain.com, I read it through mozilla thunderbird, but now I want to give it to another person who does not want to install thunderbird or similar. However he has gmail. Is it possible that he could use his gmail to read that email @myowndomain.com ? I know its possible via POP, but what about IMAP?

can't do it with Gmail afaik.

but these guys can do it if you have an account with them:
https://www.polarismail.com/Account-Consolidation/

So all these guys (many of them on this forum) who claims they are using gmail for all their emails are on crappy POP thing? Meaning everytime they want to know if they got new emails they have to manually click "update/download emails" ? Or are they on some kind of auto update thing?
reason I am asking - we need to get emails as soon as possible (like using thunderbird and IMAP) and if we have to manually download emails it would not work.

It's pop3 but it check automatically

Thunderbird will check pop automatically as often as you specify.

and downloads those emails to your gmail account or to your computer?

just setup forwarding and forward a copy to his email address

We need responses to come from the same address, not from his gmail addy..

you could access gmail via IMAP, that's what I do with all of my domains... give him the login details and done deal :)

You do not get the point. Its the other way around that we want. We want to utilize gmail's infrastructure (instead of utilizing thunderbird like we do now) to read and respond our @ourdomain.com email

You can choose who the response is from, so he would just choose the email address that is not his gmail address. He would need to add the additional address on the Accounts and import tab send mail as section.