Flood of emails sent from my email address

[grantorino357]

Hi everyone, as of a couple of days ago I have been inundated with emails that appear to be sent from my email address to me from someone somewhere in cyberspace. for example:

from: Web Designs Unlimited <[email protected]>
reply-to: ccheor <[email protected]>
to: [email protected]
date: Jun 28, 2020, 10:48 PM

What has been breached and what can I do to stop this?

Your assistance is appreciated.

[pe7er]

You've to check the email header to see how the email has been sent.

If it was your own computer / server, then you have to secure it better.

If it was some random IP address that started it: it's easy to forge an email sender addresses.
Just like in the real world you would post an envelop and put someone else's address as sender.

In all cases you could take some anti spam measures using the DNS of your domain:

• SPF (Sender Policy Framework)
  a mail server can request it from the DNS to see which other server can send mail on your behalf
  https://en.wikipedia.org/wiki/Sender_Policy_Framework
• DKIM (DomainKeys Identified Mail)
  a mail server can request a digital signature from your DNS
  https://en.wikipedia.org/wiki/DomainKey ... ified_Mail
• DMARC (Domain-based Message Authentication, Reporting and Conformance)
  is somewhat more advanced. It's to determine what to do with the mail in case SPF / DKIM check fails
  https://en.wikipedia.org/wiki/DMARC

[leolam]

One addition: https://en.wikipedia.org/wiki/Email_spoofing

Leo

[LarryK]

I had a similar situation. I found out because there were 2,225 "Mail delivery failed: returning message to sender" emails in my Inbox this morning; about 2 per minute for a day.

They were sent to "John Q. Public" from my Joomla website. I determined it was from my Joomla website as the email header indicated the web host name. I went to my Global Configuration and turned the Send Mail to NO. That stopped it. Closer look at the header; the emails were bounced back from France, Germany and Denmark email addresses. Just imagine how many Spams were delivered successfully!

Now, I need to figure out how this occurred so I can stop this in the future. I've checked my User List and User Activity Logs, nothing unusual. Any suggestions???