<?php

error_reporting(-1);

$regexp = '/([a-zA-Z0-9_+.-]+)@([a-z.-]+)/';
$text = 'fiejifewif anon@mail.ru, fesf: 124 @feef pokushat@prines.brat';

$email = array();

preg_match_all($regexp, $text, $email);

var_dump($email[0]);