The formatting of your Aliases may be good enough for Postfix but might not be exactly how iRedAdmin-Pro manages it. Could you show us an example of a line or few of these alias entries so we can tell you what's wrong with them/give you a Query to repair them?

Aliases were created as follows:

mysql> USE vmail;

mysql> INSERT INTO alias (address, goto, domain, created, active) VALUES ('name.surname@domain.it, 'my_user@gmail.com', 'domain.it', NOW(), 1);

Sample query as follows:

mysql> SELECT * FROM alias WHERE address ='vanessa@domain.it';
+-------------------+--------------------------+------+------------+--------------+----------------+--------+---------------------+---------------------+---------------------+--------+
| address           | goto                     | name | moderators | accesspolicy | domain         | islist | created             | modified            | expired             | active |
+-------------------+--------------------------+------+------------+--------------+----------------+--------+---------------------+---------------------+---------------------+--------+
| vanessa@domain.it | vanessa@domain.external  |      | NULL       |              | domain.it      |      0 | 2015-01-29 15:00:01 | 0000-00-00 00:00:00 | 9999-12-31 00:00:00 |      1 |
+-------------------+--------------------------+------+------------+--------------+----------------+--------+---------------------+---------------------+---------------------+--------+