SMTP module: The following From address failed all,

Here is something I don't quite understand. 

First of all, my site-wide email address configured on Site Information page is my_gmail_address@gmail.com.

Then, I use smtp module to send emails out from my site. I configure SMTP settings with my yahoo email address my_yahoo_mail_address@ymail.com.

I tries to send a test email out to my other gmail address my_other_gmail_address@gmail.com, but failed. Email can never be sent out in this situation.

Here is watchdog log details: 

Type    smtp
Date    Monday, September 22, 2014 - 11:29
User    lyon
Location    http://localhost:8888/drupal-test/admin/config/system/smtp
Referrer    http://localhost:8888/drupal-test/admin/config/system/smtp
Message Error sending e-mail from my_gmail_address@gmail.com to my_other_gmail_address@gmail.com : The following From address failed: my_gmail_address@gmail.com
SMTP server error: From address not verified - see http://help.yahoo.com/l/us/yahoo/mail/original/manage/sendfrom-07.html

Severity    error
Hostname    ::1
Operations  


SMTP configuration didn't go wrong, because in the following two situations, email can be sent out well:


configure site-wide email address to be the same one configured in SMTP settings: my_yahoo_mail_address@ymail.com.
configure SMTP settings with a gmail address, then configuring site-wide email address to be any email address will work well. (People on Internet says Gmail can override it).


I don't want the SMTP configuration to be tied with Gmail account, it should support any mail host. How can I overcome this problem?

I appreciate your help.
I believe the problem lies with Yahoo not having your permission to send from the gmail account.  You could try setting up Yahoo to send from your gmail account but I'm not sure Yahoo will do that.

You could look into a mail service like MailJet, which is cheap and scalable.

Or, assuming you're using the drupal_mail function, simply set your $from variable in 'params' to 'my_yahoo_mail_address@ymail.com'.