smtp-user-enum

Enumerates system users over SMTP (VRFY/EXPN/RCPT).

Enumerates valid system accounts through an SMTP server by abusing the VRFY, EXPN or RCPT TO commands: the server answers differently depending on whether the user exists.

Family Recon, DNS & OSINT

Flags -M VRFY -U -t

Concepts SMTP user enumeration (VRFY/EXPN/RCPT)

Cheatsheet SMTP · 25 / 587

Installation

sudo apt install -y smtp-user-enum

Useful commands2 commands

Appears in

Some machines where its use is documented; not an exhaustive list.

ClamAVProving Grounds Practice