Issue with webmail server

Hi,

My Webmail server is hosted remotely and is NATed through a public IP. While the login page is accessible, I am unable to log in. The network is configured with a dual-WAN setup using SD-WAN interfaces. I have observed that when one of the ISPs is disabled, I can successfully access the mail account. An SD-WAN rule has been created, but webmail access is only possible when a specific ISP is used or the other is disabled. Could you suggest a resolution that allows webmail access without relying on an SD-WAN rule or policy route?

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