synchronization problem with eml files

[GiulioP]

I am not sure if this is really an issue of the program (for sure it is an issue for me!)
I am using FFS in order to have in synch the files on the pc at work with my pc at home. Every day I use it FFS wants also to synchronize several eml files (copy of some emails created from Thunderbird) between the USB pen where I keep a copy of my work files and the pc I am currently using (either the work pc or my personal laptop).

Is there a way to avoid to synchronize all these files every time? I don't even change them at all!
thanks!
p.s. it is a wonderful program1 I have been using it for several years and I cannot work without it!

[Zenju]

https://freefilesync.org/manual.php?topic=exclude-items

[EdS]

Ditto to wonderful program !

That link helped, but here is my question:
How to sync only new/ not previously synced emails? Such as a NEW email I just saved to a folder & now I do indeed want to sync that NEW e-mail but not the 2,300 emails I have already synced?
I use Thunderbird e-mail
Here is what I put in the filter: *.eml ; this worked to exclude all emails (even a NEW email that I do indeed want to sync.

Thank you

[EdS]

Update (rather than edit my above post).
As mentioned , I put into the filter: *.eml , I have eliminated that.
I then went to the Filter’s TimeSpan window. Yes that helps. The way I have it working now is satisfactory; because if I ever see sync showing the 2,300 emails I do NOT want synced (because they were already), then that will make me go fiddle with the TimeSpan window until it gets to only showing the 8or 9 “recent-few-not-yet-synched”.
And the Show Log icon at the at the bottom left helps.
But I do want to be sure there isn't another way?
Thank you

[Plerry]

How to sync only new/ not previously synced emails? Such as a NEW email I just saved to a folder & now I do indeed want to sync that NEW e-mail but not the 2,300 emails I have already synced?

That is the nature of essentially any file-sync program, including FreeFileSync (FFS).
FFS compares the content of the left and right location, detects the left-vs-right differences and proposes and later executes sync actions based on the differences it detected and the selected sync variant.
Any files that have been previously synced and are not modified left nor right since then, will be deemed equal, and will not result in sync actions.
So, your 2,300 emails that you already synced are Compared, found to be equal and therefore not Synced again. If you do not Compare by content, comparing 2,300 files normally goes pretty fast.

[EdS]

Thank you for the reply. I failed to clarify that I know for fact there is something “different” about every one of those 2300 emails that need to get synced every time. But I have no idea what “changed”. I do understand what you are saying, that FFSync looks at 2,300 emails and only syncs the ones that have somehow “changed”. That is the thing, I have no idea how they have changed. I have not even clicked on them much less opened them. And also, it seems(?) that if I go into THE FOLDER that has the emails, even though I do not click on any email nor Open any email, for some reason something “changes” because I opened THAT FOLDER containing the emails, so free file sync picks up that “change”. The only thing I can think of is some “property” of the e-mail? Or the property when I saved it.
The other thing is: in the past (before I learned my work around above via the Filter’s TimeSpan window), I would let it sync for the 15-80min or whatever (instead of the 5 seconds it should take because there was only say 10 items to sync), then FreeFileSync would work flawlessly for weeks or months, then one day out of the blue,it finds that the 2,300 emails need syncing, because something has changed about those emails. And it is only email , no other items like MSWord document or Excel, or photos etc .
I almost always do a Mirror Sync
I do occasionally go in a Folder & change the “View” such as sorting by date instead of by “Name”.
Thank you

[Gianni1962]

Windows changes date and time of eml files with Windows search enabled.

https://www.google.com/search?q=Windows+changes+date+and+time+of+eml+files+with+Windows+search+enabled

[EdS]

You nailed it. Thanks. I swear I searched for it before coming here. If I can execute one of the suggested fixes easily, I will. Otherwise I’ll keep doing the Filter’s TimeSpan window method. When my 2,300 emails show up to be synced, I drop back 1 day. Thanks to everyone.

[Zenju]

Yes this is a known Windows bug(?)/limitation:

https://freefilesync.org/faq.php#different-after-sync

Microsoft Indexing Service (SearchProtocolHost.exe) is adding ADS streams to all .eml files after copy. This feature can be turned off with little loss.