Email suddenly stopped working last week

[RogerL]

So I have a bunch of things getting emailed regularly, and they stopped.
looking in the logs i see this:

 [TABLE="class: log_table_row, width: 970"]
[TR]
[TD="class: LogDateLong LogDateTime0, bgcolor: #ffffff, align: left"][SIZE=13px][FONT=Courier-New][COLOR=#FF0000]Nov-04 01:51:38[/COLOR][/FONT][/SIZE][/TD]
 			[TD="class: LogPri0, bgcolor: #ffffff, align: left"] [/TD]
 			[TD="class: LogType0, bgcolor: #ffffff, colspan: 3, align: left"][SIZE=12px][FONT=Courier-New][COLOR=#FF0000]Warning[/COLOR][/FONT][/SIZE][/TD]
 			[TD="class: LogEntry0, bgcolor: #ffffff, colspan: 8, align: left"][SIZE=12px][FONT=Courier-New][COLOR=#FF0000]Sending email failed with an irrecoverable error - mail not sent.[/COLOR][/FONT][/SIZE][/TD]
 		[/TR]
[/TABLE]
[TABLE="class: log_table_row, width: 970"]
[TR]
[TD="class: LogDateLong LogDateTime1, bgcolor: #ffffff, align: left"][SIZE=13px][FONT=Courier-New][COLOR=#FF0000]Nov-04 01:51:38[/COLOR][/FONT][/SIZE][/TD]
 			[TD="class: LogPri1, bgcolor: #ffffff, align: left"] [/TD]
 			[TD="class: LogType1, bgcolor: #ffffff, colspan: 3, align: left"][SIZE=12px][FONT=Courier-New][COLOR=#FF0000]Error[/COLOR][/FONT][/SIZE][/TD]
 			[TD="class: LogEntry1, bgcolor: #ffffff, colspan: 8, align: left"][SIZE=12px][FONT=Courier-New][COLOR=#FF0000]Exception creating email for sending (To:REDACTED@yahoo.com, cc:, bcc:, Sub:The hallway temp is 79.7 F, Attach:) = '@' is not a valid email address. Parameter name: address[/COLOR][/FONT][/SIZE]
[/TD]
 		[/TR]
[/TABLE]

(I replaced my actual email address above)
That's just an example of one I just manually ran, but all events using email; regardless of the address (yahoo, gmail, text/sms address, are failing with this message '@' is not a valid email address.

I have checked the events and addresses are correctly listed and shown, but HS is acting as if they are not. help??

[RogerL]

well i found the problem.... my email settings in HS under setup were blank. gone. and I don't know why.
I have not been in the guts of HS for a couple months, only looking at the front facing things and controlling things remotely.
But it stopped emailing last week, right before Halloween and I just now had a chance to go look into it.

I tried restoring from backups prior to the 27th, and none would seem to do anything, so I looked up the info and re-entered the mail info (I run a local hmail server for my network) and low and behold it works.

So can someone tell me did something happen last week? was there an update to HS3 of some kind?
Any reason why the email settings would just disappear and everything else just keep on trucking along?

[langenet]

There were no updates to HS3. I too run my own email server - actually, on the same box. Never saw this issue either. I thought this might have happened in HS4 since they use JSON for a database. I would have figured the DB in HS3 was more robust. The only thing I can think of is a MS update forced a restart and compromised the DB.

[RogerL]

Thanks for confirming. My hmail is on the same PC as well, I just have it bound to a different IP on a different network card.
still have not found any reason for the fields to blank themselves.