I'm using AcyMailing Starter 6.7.5 on Joomla. URLs look and work fine in the editing interface and in test emails but, are actually corrupted in the final mass mailing to recipients.
The URL will look correct like: https://igaircargo.ch/index.php/events/71-forum-logistikcluster-region-basel
But user click will direct to something bogus like: /index.php/component/acym/?ctrl=fronturl&task=click&urlid=23&userid=125&mailid=31
If required I can forward examples by email.
This is normal behaviour. It's the way Acymailing records your click statistics. Acymailing records the click and then redirect the user to the correct page.
In case want no tracking you can disable it in Configuration->Data collecrtion.