synchronizing messages

at one gmail account 
synchronizing messages
and nothing happens
the calender and contacts were synct
other accounts , incl. gmail, works fine
only my account didn ́t work

Are you getting any kind of error message?

Wait - how many accounts do you have?  If you have a free license, you can only have 2 accounts and the third will be ignored.

no error message

life time license

Could you verify your IMAP setting for the bad account-- should be:
Port 993
Use SSL/TLS on special port (legacy)

You also might want to try pro support-- they are pretty fast.

i have four gmail acounts tested
all the same settings
3 are allright
1 (my first) are still syncing

It looks like it is doing a full sync and it has not yet completed all accounts.  Be patient.  You will note the bottom account has no green bar yet.

Did you just add the last 2 accounts?  The first sync is always slow and then it should sync very quickly on an ongoing basis.

12 h a full sync?
only208 messages are there

The account that is currently syncing (the account with the green bar) only has 208 items?  That account seems to be the holdup.  The bottom account is just waiting for the top account to finish.

If it is truly stuck, I would delete the account and the reenter it.

I delete this account twice 
and reinstall
nothing chance
thx for your support

Since you have a lifetime license, you can use pro support.  They are pretty quick at responding.

now I have open a support ticket

Great.  When you get a resolution if you could share it with the forum that would be very helpful.

After 24 h the same issue
while the sync is working
my internet speed is under 50 k

and now
the same issue on the second gmail account

now, its working
gmail server problems?

I’ve read all of the above text. I’m getting my contacts, tasks and calendar ok but not my messages. I’ve tinkled with the server settings for over a day and read blogs but still can’t get or send messages. I have only one gmail account. My settings are imap 993 and smtp 465 as mentioned above. Also, the sync function executes ok (spinning wheel) and sync timestamp gets updated and no error messages. Windows Mail is getting and sending ok with the same gmail account. I’m using free version eM Client to trial it before purchase. The log says it’s synchronising ok with all folders and subfolders. I’ve checked my Google account under ‘Apps with access to your account’, eM Client is in the list and has access to ‘Gmail, Google Calendar, Google Hangouts, Basic account info, Additional access (tasks)’. Is eM Client good to go or are there hitches that aren’t being disclosed?