yahoo-mail
The incoming mails are received as usual but I’m unable to send mail from Yahoo mail account.
While trying to send any mail from my Yahoo account, I am getting the blank screen. Only thing is the browser address bar shows this address:
http://in-mg61.mail.yahoo.com/neo/b/compose?&.rand=381039365
What could be the possible reason and how to correct it?
You have listed the three reasons, so it's good that you are aware of them... Let's go through them:
Hacking
You handled this just fine by quickly changing your password.
Spoofing
The SMTP protocol (the connection used to send mails) allows anyone to specify the address the mail originates from. So for instance, I could send a mail from any Yahoo address without knowing any password, it's possible but it's illegal...
Most of the times, you can't do much against spam but if it's keep happening you can at least try to identify where the mails are coming from. You can do this by requesting someone who received your mail to check the mail headers and send you the data that is in there.
This allows you to inspect the IP/host it comes from and inform their ISP about the spam.
Malware explosion
You handled this just fine by verifying the computer is clean.
You have a period at the end of the email address
users-digest-subscribe@httpd.apache.org.
^
It should be users-digest-subscribe@httpd.apache.org (no period)
Removing the period gets me a reply from the Apache Digest with the subject
confirm subscribe to users@httpd.apache.org
Best Answer
Try this advice of yahoo: http://help.yahoo.com/kb/index?locale=en_US&page=content&y=PROD_MAIL_ML&id=SLN3569&impressions=false