Pattern guessing costs nothing. If you know the name and the domain, the candidates are `anna.berg@`, `aberg@`, `anna@` and `a.berg@`, and one of them is probably right.

Sending to all four is a bad idea. Three will bounce, and in cold outreach that hurts more than in regular marketing, since the sending domain is usually new and has no history to absorb it.

A verification service settles it before sending. Paste the four variants into uChecker and write to the one that comes back good.