FAQ for users
I have set up my email program but can't deliver any emails to 1&1
Please check your email program settings with your provider's recommended settings. Also make a note of the error message and try a different approach to delivering the email.
What is the maximum size for attachments that I send to 1&1 users?
The maximum size of an email is 100 MB. Please note that in case of encrypted transmission, the file size must not exceed 72 MB as the remainder is required for encryption.
We do not recommend sending emails with attachments of this size. This can cause extremely long download times and/or cause various error messages.
Why are my emails not being delivered?
Whenever an email can't be delivered, 1&1 always sends an error message to the original sender. Please refer to the list of error messages to discover the reason why your email couldn't be sent.
My emails are not being delivered. Why am I not seeing an error message?
Whenever an email can't be delivered, 1&1 always sends an error message to the original sender. Please check if the error message was identified as spam or moved to another folder due to a filter rule. Please also check whether the email system you use actually forwards error messages to users.
My question wasn't listed. How can I contact 1&1?
If you have questions about your 1&1 Web Hosting Package, refer to the Help and Contact Information, or contact 1&1 customer service directly.
If you have any further questions about sending emails to 1and1, you can contact us by using the contact form.
