To overcome these limitations, Microsoft introduced native external sender callouts in Outlook. Multiple external tag s : If the external users keep replying to the thread, it will add multiple tags i n t h e subjec t.As the transport rule might not be aware of the end user’s language, it leads to localization issues.It takes a lot of space in the subject line, making it hard to preview the subject.For these years, admins use a transport rule to prepend in the subject line. It plays a vital role in protecting against spam and p hishing threats.
External email warning helps to alert users from clicking malicious links, phishing emails sent by external senders.
