You have deployed the e-securemail for Microsoft 365 solution and you are noticing false positive alerts on some e-securemail links?
Safe Links is a Microsoft Defender for Office 365 feature designed to protect against attacks by analyzing links contained in emails or other messages in order to detect potential threats. However, harmless links may sometimes be blocked by mistake.
To avoid incorrect link blocking (false positives), add the following URLs to the trusted links list in Microsoft Defender.
Links:
cim.security-mail.net/*
preview.security-mail.net/*
protectlink.security-mail.net/*
security-mail.net/*
Secuserve guide:
Knowledge Base – Allow the ProtectLink URL (security-mail.net)
Microsoft Defender article:
Complete Safe Links overview for Microsoft Defender for Office 365 - Microsoft Defender for Office 365 | Microsoft Learn
You can also follow the customer allow/block list procedure:
https://security.microsoft.com/tenantAllowBlockList