I was thinking about something, and I came across with a question. Can an email be sent to an ip? instead a domain name? example: theemail@111.111.111.111 supposing that the ip is static?
No, because an IP doesn't mean it's a domain. I've got an IP address (my server), which has about 20 websites on it. You'd need to specify the domain.
if it is a public IP address hosting one site, it could be possible. I have not heard of this before, but it is possible that it would work if the ip is connected to a website.
It is possible, given varrious conditionals are met. No I don't know what all has to be met. You couldn't just send to an IP address however, it would have to be: where you are simply replacing the domain after the @ with the IP address. If the site has a dedicated IP i'm sure this is possible. Some email providers require you to wrap the IP address in square brackets '[ ]' so give that a try. IE: contact@[192.168.1.1]