More information is needed, as a bounce is normally a message being returned to sender, yet your post indicates the bounce went to the receiver. Did you send a message with a large attachment and this might be a notice to you?

Thanks David! Your question is my quandary as well. The following is the message I get:

"A message was sent to you that was returned to the sender(bounced) because it would have caused your mailbox quota to be exceeded.

The following is the reason that the message was over quota:

      Quota Type: bytes in the message
 Quota Available: 25000.0KB
     Total Quota: 25000.0KB

The following is the information on the message that was bounced:

     Sender: Mail Delivery Service <postmaster@optonline.net>
    Subject: Delivery Status Notification
       Size: 70830899
 Message ID: 73a64b4c-5715-11ef-a763-cb6bd06a67b5
       Date: Mon Aug  5 19:41:03 2024

   Reply-To: 

The message was bounced from the following folder:

   INBOX

To fix this problem, delete some messages from your mailbox, and contact the sender to resend the message.

If the size of the message is too big, contact the sender to reduce the size of the message and resend the message."

I did send a message with many pictures attached. It bounced back and the receiver did not get the message. However, since then I have received this message 10-15 times. As you can see, the bounce indicates it results from a message coming to me...not from me. If this is indeed the result of my large message from days ago, how do I stop it. If it the result of a message sent to me, how do I find out who is sending it?

Thank you!!!!!!!

Puzzling. I've never seen such a message. If optonline.net (optimum) is your email provider, then odds are the message relates to you. If not, the sender has received the bounce notice and knows the message was not received, so no real need to figure who it is. What I find frustrating is that the wording implies that it's YOUR fault that the message was too big for you to receive. Weird.

IKR, Weird. Who freakin knows. Thanks for looking into it for me. Didn't solve anything, but sure does help!!

That is an over quota error from the mail server.

The solution is included in the message

To fix this problem, delete some messages from your mailbox, and contact

the sender to resend the message.

So now the obvious next question is what is quota. That is the amount of space your mail provider has offered for you to store mail in your account. Each provider makes their own decisions about what quota to offer and how you are notified when it is exhausted. But the error message you are receiving is fairly standard for over quota errors. Given that sent mail is stored on the mail server in the sent folder, it is quite possible to have mail you send bounced from your account when the mail is uploaded without that specific error occuring.

So how much is your storage quota. A google search of optonline turned up this http://help.webhosting.optonline.net/documents/rd/gb/gettingstarted/old/Managing_Domain_Names/Update_DNS_and_MX_Records/faq_email.htm

Is there a limit to the number of messages I can have in my mail box? So long as an email account remains below its size quota (for example, it's 75 MB on the Gold Plus Plan), there is no limit to the number of messages. If you would like to increase your email account's quota, then in the Email section of SiteControl click Change Quota next to the appropriate email account. What is the maximum size for an email attachment? You can send and receive attachments up to 10 MB in size, as long as this does not cause your mail box to exceed the email account quota as determined by your plan. The mail server limits all outgoing and incoming emails to 10 MB.

So you can have 75Mb of mail in your mail account at anyone time with that mail provider. Google offer 15gb and Yahoo something like a terabyte. But they are making money of your data unlike a hosting service which is also profit driven.

Essentially your ability to act as a pack rat with email on an optonline provided account is severely limited. I would strongly suggest you try archiving some of your mail to the Thunderbird local folder. Local folders can store as much mail as your local hard disk has space for, but you are responsible for enabling and maintaining suitable backups as there is no copy stored on someone else's machine somewhere else (the cloud). This is particularly important for business owners that have legal obligations to hold copies of business records(of which email is one) for sometimes decades.

Also ensure that the deleted folder is emptied regularly, probably on shutdown in the account settings and that the account expunges at the same time as expunge is when the IMAP server gets it's space used by deleted emails back.

Wow! Thanks for the work Matt. I'll get to deleting and moving old stuff.