[imp] Unable to reply to emails using basic mode

[Patrick Domack]

It just reports that an error has been logged, and won't reply to  
emails. New emails work fine though.

This is logged when reply is clicked:
Couldn't resolve host 'chrome-extension' [pid 12011 on line 118 of  
"/usr/share/php/Horde/Http/Request/Curl.php"]

and I'm also seeing a lot of lines like this for the user:
[imp] PHP ERROR: Undefined offset: 16 [pid 12011 on line 365 of  
"/var/www/mail/imp/lib/Mailbox/List.php"]


horde 5.0.3 and imp 6.0.3