On Monday morning we found out that large incoming mails (1 MBytes or larger) were dropped without leaving any error messages in our log files. These mails were lost between Thursday (Jan 9) evening 18:27 and Monday (Jan 13) morning 11:06. Some indicators (i.e. spam filter rules for this case) lead us to estimate the number of about 560 broken local deliveries to about 300 unique recipients.
If you expected e-mails with attachments close to 1 MB or larger within this time frame there is a high likelihood that they got lost. The only information we still have about these mails are sender, recipient and arrival date and time. If you were one of these recipients, please contact the sender to send it again.
You can check on this web page if mails you should have received were lost. You'll have to log in with your D-PHYS account and will see sender (or mailing list) of and time when the lost mail arrived. Additionally we'll inform all affected recipients individually, too.
The problem occured after one of the software updates on Thursday which brought stricter code checking, and is solved since Monday morning 11:06.
The issue was caused by a long standing and subtle programming error in the check which prevents bigger mails from being inspected closely by the main spam filter for performance reasons. It was only triggered upon local mail delivery, so mails sent from D-PHYS to outside D-PHYS were not affected. E-mails to D-PHYS mailing lists (or other mailing lists) with archive should be available in the according mailing list archives.
We're truly sorry for any inconvenience this may have caused and have already taken measures so that similar issues won't result in mail loss from now on.
Update: it happens to the best of us: Gmail for iOS bug might cause data loss