mail.com Not Working? Fixes for Missing Emails and Bounces

Most mail.com problems are one of three things: messages are being moved by a setting, messages you send are bouncing, or an email program can’t connect. Start with the section that matches.

Emails are missing

• Search first. mail.com’s search also looks in Trash and Spam — quicker than checking every folder by hand.
• Spam folder: wanted messages can land there by mistake. Use Not Spam and the allowlist so the filter learns.
• Filter rules: a rule you set up in the past may be sorting or deleting messages automatically. Deactivate any that send wanted mail away from your inbox.
• Folder storage times: a folder set to keep messages for a limited time moves older ones to Trash. Check the storage times of your folders, including Spam and Trash.
• An email program using POP3 can remove messages from the server. In its POP3 settings, choose Leave a copy on the server.
• On your phone? mail.com suggests its Mail App, so you don’t have to adjust server settings at all.

Emails you send come back

The code in the bounce tells you what happened. mail.com explains that 400 codes generally mean a temporary problem — the system often keeps retrying, so wait and try again later. 500 codes mean the email can’t be delivered at all, so you may need to act. (More in SMTP error codes explained.)

• “Mailbox unavailable” or “Unknown user”: check the address and domain in the error message, fix any typo and resend.
• “Mailbox quota exceeded” or “too many messages”: the recipient’s mailbox is full. Call them or send a short note asking them to clear space.
• Large attachments: make them smaller — for example, send a ZIP file — or share the files from mail.com Cloud instead.
• Bounces for email you never sent: spammers can forge your address without getting into your account. mail.com still recommends an antivirus scan, then a new password, and warning your contacts. Don’t open attachments in unexpected bounce messages. See mail.com security.

Outlook, Apple Mail or your phone can’t connect

• Free account? mail.com says POP, IMAP and SMTP are Premium features only, so free accounts can’t connect other email programs. Use the website or the mail.com Mail app.
• Premium account? POP3/IMAP access is off by default. Go to Email › Settings › POP3 & IMAP, tick Enable access to this account via POP3 and IMAP and click Save. mail.com also switches it off automatically if you don’t use it for a long time — so check it again if a program suddenly stops working.
• Using two-factor authentication? The program needs an application-specific password, not your normal one.

Server names: mail.com server settings. Can’t log in at all? See logging in to mail.com.