Emails not going out from workflows/alerts on SharePoint 2013

[Test SharePoint]

The emails are not going out from any Wf's or alerts on my SP2013.

I have a single server architecture.

I have checked the outgoing email server settings: I am bit unsure about the outgoing SMTP server. What would be the best way to confirm this?

I have checked the IIS6.0 manager and confirmed the authentication.

Also I checked the folder: inetpub]badmail: I see all emails stuck there.

Action: failed
Status: 5.7.57
Diagnostic-Code: smtp;530 5.7.57 SMTP; Client was not authenticated to send anonymous mail during
Content-Type: message/rfc822

Any help would be appreciated.

thank you

[#2]

What are you relaying off of? Make sure you didn't have a certificate expire on the endpoint there would be first place I would check if this just randomly happened. If it's exchange, should be able to go to ECP and check the certificates on the server tab.

[#3 · Accepted solution]

Could also be that the connector changed?

I would install telnet if you don't have it on the SharePoint server, then telnet relayIP 25
Then you can do like
helo yourdomain.com
mail from:you@yourdomain.com
rcpt to:something@yahoo.com
data
.

to test the smtp connection from the server.

[#4]

Make sure the mail server you're relaying off of is configured to allow traffic from the SharePoint server.

[#5]

thank you very much