Emails are not sent by forum anymore

[LiBen]

Hello,

Running SMF 1.1.19 forum is on a sub-domain hosted but with a separate name. (reduction of the expenses for a free service)
Emails went out by PHP-standard, settings are still as such.

• The main issue
  
  When a new member registers myself and the moderators get a notification by email. This has been ever since we started.
  
  After the 6th of May it suddenly stopped! I didn't make any changes around that time.
  
  Strangely on the 26th of May we got the notifications of that day. I was happy that it was fixed (by itself) but from the next day on it stopped, again.
  
  Also at the same time (May 6th) the copy emails of all PM's stopped.
  
  I don't any report of undeliverable emails and I have sent myself and the moderators PM's but only the PM's arrive and the copy emails never do so.
  
  According to the host, it's a SMF-problem.
  
  
  
• For a longer while I get an error report which probably isn't related as it excisted long before:
  but just in case...
  
  forum.tld/index.php?action=register2
  Database error: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ' '', 3, 10)' at line 3
  File: /var/www/vhosts/main.site/subdom/name/httpdocs/Sources/Subs-Members.php
  Line: 825

Any help is welcome.

[vbgamer45]

Can you attach your Sources/Subs-Members.php file

[LiBen]

Sources/Subs-Members.php attached.

[LiBen]

The main issue is the notification by email, which is not working.

[kat]

* K@ wonders what vbgamer45 was gonna look at, in that file...