#sending email does not work (and it worked before) 
#output from /var/log/mail.info 

May 21 06:40:40 server postfix/smtpd[2745]: NOQUEUE: reject: RCPT from web35902.mai
l.mud.yahoo.com[66.163.179.186]: 554 5.7.1 <tmroland@assa-electronic.ro>: Relay acc
ess denied; from=<tmircearoland@yahoo.com> to=<tmroland@assa-electronic.ro> proto=S
MTP helo=<web35902.mail.mud.yahoo.com>
May 21 06:40:40 server postfix/smtpd[2745]: disconnect from web35902.mail.mud.yahoo
.com[66.163.179.186]