Mail: "indicator" failed

 

Hello,

I have used my custom indicator to send mail alerts with no problems on VPS for a couple of weeks then it stopped. I went to check the Journal I found ----Mail:"indicator"failed----- I did not change any setting the indicator may send in average about 10 notifications/24 hours...and test message will give the same issue----SMTP server/password setting are the same---nothing at at all changed why it is not working? any help?