New users with the same mail server register in the online store, who are they?

Question

Email

For the last month already the 3rd user registration, by email, which everyone has one: name @popdieta.pl
After registration, the password is changed. That's all for now.
What kind of popdieta.pl is not clear, search engines do not write anything intelligible.
In the metric, Yandex also does not show the actions of the one who registers.
In general, who or what is it, did someone come across something similar?

Answer 1

Usually they are spammers.

Answer 2

What kind of popdieta.pl is not clear, search engines do not write anything intelligible.

How is that?