smtp port forwarding

[almerilinux]

Hi opnsense users
After testing several firewalls to incorporate into a production environment. I finally chose opnsense, but now I have been having a problem for a few days and I can not find the solution.
I would appreciate if someone can help me solve it.
The problem is:
I have a mail server behind OPNsense 19.1.4-i386,  I have configured nat forwarding in 993,465, 587,.. and 25 ports, and everything works fine except port 25 does not send email outside the firewall.
I have made some checks like

traceroute -n -T -p 25  gmail-smtp-in.l.google.com
resulting in:

 1  * * *
 2  * * *
 3  * * *
 4  * * *
 5  * * *
 6  * * *
 7  * * *
 8  * * *
 9  * * *
10  * * *
11  * * *
12  * * *
13  * * *
14  * * *
15  * * *
16  * * *
17  * * *
18  * * *
19  * * *
20  * * *
21  * * *
22  * * *
23  * * *
24  * * *
25  * * *
26  * * *
27  * * *
28  * * *
29  * * *
30  * * *

it seems that SYN is blocked

any suggestions, please ?