SRC Address for Email

Hi Team,

One of our Mikrotik Router is connected with Two WAN (WAN1 and WAN2).

We use Netwatch Option to Monitor our Servers IP and Send UP and DOWN Emails.

Our Email Server Only accepts smtp from WAN2 IP address.

But in Mikrotik Tools Email there is no option to mention the Src. Address.

Can anyone help me with this or is there any other alternate solution to this issue???

So if wan2 goes down, you will not get any email at all since only wan2 can send email?

/ip route
add distance=1 dst-address=123.123.123.123/32 gateway=10.199.199.1 routing-mark=to_SMTP
/ip route rule
add action=lookup-only-in-table dst-address=123.123.123.123/32 table=to_SMTP

Yes, We just wan to monitor one of our server and our WAN2 is most reliable as it is connected to Core Routers