https://calendar.mail.ru not synced, because it is not implement correctly an “OPTIONS” webdav-request. Please, add feature to skip “OPTIONS” and use default options if caldav server not return options correctly.
See “Em Client” implementation of this feature (captured by fiddler), by example:
OPTIONS https://calendar.mail.ru/ HTTP/1.1
User-Agent: eM Client/6.0.21040.0
Accept-Encoding: gzip, deflate
Host: calendar.mail.ru
Content-Length: 0
Connection: Keep-Alive
HTTP/1.1 302 FOUND
Server: nginx/1.5.11
Date: Thu, 25 Dec 2014 07:20:33 GMT
Content-Type: text/html; charset=utf-8
Transfer-Encoding: chunked
Connection: close
X-Frame-Options: SAMEORIGIN
Location: https://calendar.mail.ru/login/?page=/
Strict-Transport-Security: max-age=31556926
X-XSS-Protection: 1; mode=block
X-Content-Type-Options: nosniff
Content-Security-Policy: default-src *.mail.ru *.imgsmail.ru *.yadro.ru *.facebook.com *.vk.com *.odnoklassniki.ru *.ok.ru *.tns-counter.ru *.youtube.com; script-src ‘unsafe-inline’ ‘unsafe-eval’ *.mail.ru *.imgsmail.ru *.yadro.ru *.facebook.com *.vk.com *.odnoklassniki.ru *.ok.ru *.tns-counter.ru *.youtube.com *.twitter.com; style-src ‘unsafe-inline’ ‘unsafe-eval’ *.mail.ru *.imgsmail.ru *.youtube.com; img-src data: *; report-uri https://cspreport.mail.ru/calendar/;
0
OPTIONS https://calendar.mail.ru/login/?page=/ HTTP/1.1
User-Agent: eM Client/6.0.21040.0
Accept-Encoding: gzip, deflate
Host: calendar.mail.ru
Content-Length: 0
HTTP/1.1 200 OK
Server: nginx/1.5.11
Date: Thu, 25 Dec 2014 07:20:33 GMT
Content-Type: text/html; charset=utf-8
Transfer-Encoding: chunked
Connection: close
X-Frame-Options: SAMEORIGIN
Strict-Transport-Security: max-age=31556926
X-XSS-Protection: 1; mode=block
X-Content-Type-Options: nosniff
Content-Security-Policy: default-src *.mail.ru *.imgsmail.ru *.yadro.ru *.facebook.com *.vk.com *.odnoklassniki.ru *.ok.ru *.tns-counter.ru *.youtube.com; script-src ‘unsafe-inline’ ‘unsafe-eval’ *.mail.ru *.imgsmail.ru *.yadro.ru *.facebook.com *.vk.com *.odnoklassniki.ru *.ok.ru *.tns-counter.ru *.youtube.com *.twitter.com; style-src ‘unsafe-inline’ ‘unsafe-eval’ *.mail.ru *.imgsmail.ru *.youtube.com; img-src data: *; report-uri https://cspreport.mail.ru/calendar/;
Content-Encoding: gzip
5d86
<…bad html page…>
0
PROPFIND https://calendar.mail.ru/ HTTP/1.1
User-Agent: eM Client/6.0.21040.0
Accept-Encoding: gzip, deflate
Content-Type: text/xml; charset=utf-8
Accept: text/xml
Brief: t
Depth: 0
Host: calendar.mail.ru
Content-Length: 123
<?xml version=“1.0” encoding=“utf-8”?><D:propfind xmlns:D=“DAV:”><D:prop><D:current-user-principal /></D:prop></D:propfind>
HTTP/1.1 301 MOVED PERMANENTLY
Server: nginx/1.5.11
Date: Thu, 25 Dec 2014 07:20:33 GMT
Content-Type: text/html; charset=utf-8
Transfer-Encoding: chunked
Connection: close
X-Frame-Options: SAMEORIGIN
Location: https://calendar.mail.ru/principals/
Strict-Transport-Security: max-age=31556926
X-XSS-Protection: 1; mode=block
X-Content-Type-Options: nosniff
Content-Security-Policy: default-src *.mail.ru *.imgsmail.ru *.yadro.ru *.facebook.com *.vk.com *.odnoklassniki.ru *.ok.ru *.tns-counter.ru *.youtube.com; script-src ‘unsafe-inline’ ‘unsafe-eval’ *.mail.ru *.imgsmail.ru *.yadro.ru *.facebook.com *.vk.com *.odnoklassniki.ru *.ok.ru *.tns-counter.ru *.youtube.com *.twitter.com; style-src ‘unsafe-inline’ ‘unsafe-eval’ *.mail.ru *.imgsmail.ru *.youtube.com; img-src data: *; report-uri https://cspreport.mail.ru/calendar/;
0
PROPFIND https://calendar.mail.ru/principals/ HTTP/1.1
User-Agent: eM Client/6.0.21040.0
Accept-Encoding: gzip, deflate
Content-Type: text/xml; charset=utf-8
Accept: text/xml
Brief: t
Depth: 0
Host: calendar.mail.ru
Content-Length: 123
<?xml version=“1.0” encoding=“utf-8”?><D:propfind xmlns:D=“DAV:”><D:prop><D:current-user-principal /></D:prop></D:propfind>
HTTP/1.1 401 UNAUTHORIZED
Server: nginx/1.5.11
Date: Thu, 25 Dec 2014 07:20:33 GMT
Content-Type: text/plain
Transfer-Encoding: chunked
Connection: close
X-Frame-Options: SAMEORIGIN
WWW-Authenticate: Basic realm=“Calendar.mail.ru”
1a
401 Authorization Required
0
PROPFIND https://calendar.mail.ru/principals/ HTTP/1.1
User-Agent: eM Client/6.0.21040.0
Accept-Encoding: gzip, deflate
Content-Type: text/xml; charset=utf-8
Accept: text/xml
Brief: t
Depth: 0
Authorization: Basic pbmUucnU6SGpjY2J6MjAxOA==
Host: calendar.mail.ru
Content-Length: 123
<?xml version=“1.0” encoding=“utf-8”?><D:propfind xmlns:D=“DAV:”><D:prop><D:current-user-principal /></D:prop></D:propfind>
HTTP/1.1 301 MOVED PERMANENTLY
Server: nginx/1.5.11
Date: Thu, 25 Dec 2014 07:20:33 GMT
Content-Type: text/html; charset=utf-8
Transfer-Encoding: chunked
Connection: close
X-Email: blabla@mail.ru
X-Frame-Options: SAMEORIGIN
Location: https://calendar.mail.ru/principals/users/blabla@mail.ru
Strict-Transport-Security: max-age=31556926
X-XSS-Protection: 1; mode=block
X-Content-Type-Options: nosniff
Content-Security-Policy: default-src *.mail.ru *.imgsmail.ru *.yadro.ru *.facebook.com *.vk.com *.odnoklassniki.ru *.ok.ru *.tns-counter.ru *.youtube.com; script-src ‘unsafe-inline’ ‘unsafe-eval’ *.mail.ru *.imgsmail.ru *.yadro.ru *.facebook.com *.vk.com *.odnoklassniki.ru *.ok.ru *.tns-counter.ru *.youtube.com *.twitter.com; style-src ‘unsafe-inline’ ‘unsafe-eval’ *.mail.ru *.imgsmail.ru *.youtube.com; img-src data: *; report-uri https://cspreport.mail.ru/calendar/;
0