My survey can send email before. However, occasionally I changed Force HTTPS from off to Don't force on/off, the survey will not send email any more. Even I changed it back to Off. My survey will not send email. Can any body let me know how to resolve this problem? Thanks.

The limesurvey is 2.73.1+171220, php 7.2.


By the way, there is a small error: the number of * of password under Configuration----Global settings---Bounce settings is not correct.