The email message cannot be sent. Make sure the outgoing email settings for the server are configured properly

 I did a workflow with SP Designer....and i have some workflows that presents the next problem...:

I'm receiving this workflow log message, but i revised the e-mail settings and that are propertly configured.

I was reading some topics subjects and i did some configurations like:

• Enable the feature "IssueTrackingWorkflow"
• configured timer job-immediate-alerts&properties
• update “updatealerttemplates”
• review exchange server logs

the rare case is that only happens with a some users and not others,

Thanks!