Neomail, horde strange error

Hello,

I am trying to compose a mail in Noemail and i get this message :

Neomail error :
Couldn't open /home/ben/mail/mydomain.com/nick

hordemail is not allwoing me to login. pasword not accepted.

squirremail is giving me this errors :

Warning: open(/tmp/sess_3664c93cf422b974042433e010cdba51, O_RDWR) failed: Input/output error (5) in /usr/local/cpanel/base/3rdparty/squirrelmail/functions/global.php on line 285

Warning: Cannot add header information - headers already sent by (output started at /usr/local/cpanel/base/3rdparty/squirrelmail/functions/global.php:285) in /usr/local/cpanel/base/3rdparty/squirrelmail/functions/i18n.php on line 1164

Warning: Cannot add header information - headers already sent by (output started at /usr/local/cpanel/base/3rdparty/squirrelmail/functions/global.php:285) in /usr/local/cpanel/base/3rdparty/squirrelmail/src/redirect.php on line 69

The other mail accounts are working fine. I am just wondering how a test mail account works fine and this particular mail account is giving me errors. any ideas??