SuiteCRM send email error

I have added an action- Send Email in a workflow and it didn’t work.
Then I directed to the user-edit page who I had put in the workflow and there I clicked [Send Test Email] to test and I got the error “The administator has not yet configured the default outbound account. Unable to send test email.” What’ made me confused is that I had configured outbound accout in both “Email Settings” and “Outbond Email” , and it worked when I clicked “Send Test Email” in both pages.
Then I had debug on [Send Test Email] in user-edit page, what caused the error is that the value of ID=mail_smtpserver is null, but the Email Provider shown in user-edit page is not null!
Does anyone can tell what’s happen?

Maybe you could tell us your version of SuiteCRM?

If you have any messages in your logs, can you post the exact text of the message? Thanks.

SuiteCRM Version 7.9.1.
When my workflow executed, sent mail failed and log as below:
Mon Jan 8 16:43:23 2018 [23034][1][FATAL] SugarPHPMailer encountered an error: An outgoing mail server is not configured to send emails. Please configure an outgoing mail server or select an outgoing mail server for the mail account that you are using in Settings >> Mail Account.
Mon Jan 8 16:43:23 2018 [23034][1][FATAL] SugarPHPMailer encountered an error: SMTP connect() failed.

But I have set an outgoing mail server for the user . Additionally,I have clicked [Send Test Email] in outgoing Email setting and it works!

There have been dozens of Email bugfixes since SuiteCRM 7.9.1… the first thing to try is an upgrade.

As with any upgrade, I always recommend a full backup before attempting it.

Yes, I have tried upgrade to the latest version. But after upgraded the version, I found another problem that in “Workflow Module” I had tried create an action -“create record”-- create a task and I found the task field “assigned to” was not listed in dropdown list of “Add Field”, which is more terrible for me .Could you help?

Does this look like the issue you have?