Linux mail command : HTML content in office 365 email is visible as plain text while it is correctly visible in gmail

问题

I'm trying to send out some HTML content via email using mail linux command. I'm on CentOS 7.

mail -s "$(echo -e "This is Subject\nContent-Type: text/html")"  gpsanjeewaa@gmail.com pradeep.sanjeewa@axiatadigitallabs.com <  /var/www/html/report.html

Office365

Gmail

What is the reason for this different behavior and how can I resolve this?

来源：https://stackoverflow.com/questions/62305071/linux-mail-command-html-content-in-office-365-email-is-visible-as-plain-text-w