email vs emails

"Emails" is correct; you use the plural form. If you received many emails in a day you could say either, "I got lots of email today" or "I got lots of emails today" but in your example you need to use "emails".

Thanks, hightor!

That maybe true in America, but over here one would never say "l got lots of email today."

Either I got lots of emails or I got a lot of email.

Email can be a collective or singular noun.

I got email today. or I got emails today.

When designating a number, use the plural “emails.”

Yes, since the term "email" is derived from "mail" it shares some of the usage characteristics.

"I got lots of mail today."
"I got lots of email today."

A "lots of mail" would mean that there was good number of letters, circulars, bills, and periodicals in your physical mailbox.

But "lots of email" means a lot of individual emails in an online mailbox. Since all email has the same format in your inbox – sender's name and subject – it was natural to refer to them individually as "emails", whereas you would never say lots of "mails" when referring to letters, circulars, bills, and periodicals.