Sorry to bother you, guys. I already found the culprit and to my surprise it was not a Squirrelmail setting. It was a setting in the POP3 server from Mercury. Fokke -- View this message in context: http://squirrelmail.5843.n7.nabble.com/Mails-lost-in-mailserver-after-opened-up-by-Squirrelmail-tp25747p25749.html Sent from the squirrelmail-users mailing list archive at Nabble.com. ------------------------------------------------------------------------------ Flow-based real-time traffic analytics software. Cisco certified tool. Monitor traffic, SLAs, QoS, Medianet, WAAS etc. with NetFlow Analyzer Customize your own dashboards, set traffic alerts and generate reports. Network behavioral analysis & security monitoring. All-in-one tool. http://pubads.g.doubleclick.net/gampad/clk?id=126839071&iu=/4140/ostg.clktrk ----- squirrelmail-users mailing list Posting guidelines: http://squirrelmail.org/postingguidelines List address: squirrelmail-users@xxxxxxxxxxxxxxxxxxxxx List archives: http://news.gmane.org/gmane.mail.squirrelmail.user List info (subscribe/unsubscribe/change options): https://lists.sourceforge.net/lists/listinfo/squirrelmail-users