Single domino serverwhich interect internet

UrGent:-Plz solve the issue.We have a client who is having a single server where domino 8.5 is installed. Their domain name is registered and have public Ip also.

They donot have any firewall or spam server. they want the same domino server interacting the Internet. two network card is there on server… for one network card we have given Internal IP (192.***) and for other Network card we have Provided the Public IP.

Internal Mails are happening as well as mail from outside like gmail/yahoo to domino server is successfully happening…

but mail from domino server to internet (Gmail/Yahoo) is not happening…

kindly suggest me what is the issue… what all I should do…

kindly reply as soon as possible…

shyamk.sonata@gmail.com

9718401294