Civimail is inserting a path for the open tracking image that includes var/www/html
example where it does not work https://(domain.org)/var/www/html/sites/all/modules/civicrm/extern/open.php?q=nnnn
for some mailings the path is correct: https://(domain.org)/sites/all/modules/civicrm/extern/open.php?q=nnnn
The tracking works when I manually remove the var/www/html from the path for a given url and the open report shows the open
There have been no changes to the default directory or resource paths.
Anyone else see this behavior? It seems to have started in November (2016) but is inconsistent. Any suggestions on where to look?