E-mail undeliverable: It could be because of this

If you receive a message that an email you sent is undeliverable, there can be many reasons. We will show you in which cases an email cannot be delivered.

Undeliverable email: possible causes

Whether in Outlook, at Web.de or GMX - the reasons why an email cannot be delivered are always the same.

• In any case, you will receive a notification that an email could not be delivered to the addressee. You will usually find the reason for the error there.
• If you read the notification "Mailbox not found", "Invalid mailbox" or "Unknown user", you should check whether a typing error has crept into the email address.
• The recipient may have canceled his mailbox and is using a different email address.
• If your notification contains the reason "Mailbox not found", the recipient may also have an error. In some cases, this problem resolves itself. Try sending the email again.
• An email cannot be delivered even if the recipient's mailbox is full. However, you will not receive any information about this. If necessary, you can contact the recipient otherwise and inform them that their mailbox is full.
• Typically, email mailboxes are limited in terms of message size. This applies to both outgoing and incoming messages. The e-mail could possibly not be delivered because you sent an attachment that was too large.

Our next practical tip will tell you whether you can hide your own email address.