This is a simple version of Why are auto-responders (and delayed bounces) bad?.

Lately, people find their automatic responses are being reported as spam, causing their mailservers ("auto-responders") to be listed by the SCBL and therefore blocked or filtered by some other mailservers, causing some of their email messages to not be delivered (the messages either bounce or disappear). These auto-responders respond either to every forged and legitimate email message, or only to those messages which are sent to certain primary victim mailboxes, like full or nonexistent ones or those of people who are on vacation, or only to messages sent to those mailboxes which are protected by bouncing content filters, or only to messages sent to those mailboxes which are configured for a pre-programmed response for any other reason. Spam and virus/worm email messages are almost always forged to look like they are "from" an unrelated third party, the secondary victim. When an auto-responder receives one of these forged messages, the auto-responder in turn sends a misdirected auto-response email message (a misdirected auto-response) to the secondary victim. Such misdirected bounces are now considered abusive and reportable by SpamCop per the "Messages which may be reported" section of On what type of email should I (not) use SpamCop? and are very annoying, especially on accounts that receive hundreds per day (I have one such account that is a perpetual secondary victim). On behalf of secondary victims everywhere, we SpamCop Reporters now Report misdirected auto-responses sent by auto-responders, causing the SCBL listing, blocking, filtering, bouncing, and disappearance referred to above.

The several types of auto-responders and auto-responses are detailed in Why are auto-responders (and delayed bounces) bad?.

This is another simple version:

Automatic Responses (Mailwasher 'bounces', Challenge/Response, out of office replies, and any email that is answered automatically with another email) were useful until the spammers and virus/worm writers started forging the 'From.' In fact, it used to be common practice for ISPs to accept all email and then respond with 'undeliverable' if the mailbox was no longer available.

Now spam does not only come directly to you, but also is 'bounced' to you because your email address is forged in the 'From.' (The spammers use the same lists they use to spam for forging the 'From.') Automatic responses have become the same problem as spam and cannot be used any longer. They are objectionable to recipients who never sent the original email and can even cause denial of service to innocent third parties. (Jeff G receives hundreds of these Automatic Responses every day.)

Such Automatic Responses (also called Misdirected Bounces) are now considered abusive and reportable by SpamCop per the "Messages which may be reported" section of On what type of email should I (not) use SpamCop?

The mailserver that is sending Automatic Responses can be listed on the SpamCop Blocklist by reports from users or spam traps. Some ISPs use the SpamCop Blocklist to either return (reject at server) any email from such mailservers. Others may simply delete such emails.

If your email service uses any kind of Auto Responses, your email may be blocked or tagged as spam by those ISPs who use the SpamCop Blocklist.

The several types of auto-responders and auto-responses are detailed in Why are auto-responders (and delayed bounces) bad?.

Miss Betsy, I would suggest one minor change.
In reference to the "From" line should also be the "Reply to" line as dependant upon how the auto replies are set up they may bounce to either the From or the Reply to address

Since this was supposed to be a 'simple' version, I deliberately didn't reference both. For non-techies, it adds jargon; for non-English speaking techs, it adds words to translate and they must realize that From also includes 'reply to' or 'return path' If the latter have doubts, they can ask.

Miss Betsy