Email Troubleshooting
Import/Export | Outlook | Gmail | Mac Mail | IMAP

Dealing with Email Issues
If you have issues connecting with the Internet generally, you'll be unable to send or receive email. See Internet Connection Issues for troubleshooting tips.
See Computer Basics & Terminology for help with technical terms.
Importing/Exporting Mail, Contacts & Settings
When changing email programs, you'll want to import the mail, contacts and settings from the old program to the new one.
Many programs will import this information from the most common current programs and even a few of the older ones.
- Thunderbird can natively import/export address books, mail and settings in a number of formats.
- The Bat! imports and exports email messages in .MSG, .EML and UNIX mailbox formats and now supports Exchange Web Services (EWS) protocol.
- Outlook see Outlook Resources for help in importing/exporting with Outlook.
Third-Party Import/Export Programs
However, many obsolete programs might need an intermediary program when moving to a more recent email client.
These programs match the format of the data from program you're exporting from and convert it to the one you're importing this information into.
- Aid4Mail MBOX Converter (free edition) converts mbox-type mailboxes to EML files.
- Aid4Mail (from US$29.95) is an easy-to-use migration tool that can also archive mail.
Email Backup Software
You can use email backup software to both secure your important emails from loss as well as to restore it to another installation.
- Best free email backup software for Windows 10 from The Windows Club.
- How to backup Gmail emails using UpSafe GMail Backup freeware.
- MailStore Home is a free email archiving software for Windows PC.
Outlook Resources
If you are an Outlook user, I neither run nor recommend Outlook so I cannot provide a decent level of support.
I strongly recommend The Bat! Professional as a more secure alternative that supports many Outlook features including Microsoft Exchange Web Services.
Winmail.dat issues may affect users of non-Microsoft email programs, but is invisible to Outlook.
Use Only Supported Versions
Use only a currently-supported version of Outlook (automatic in Microsoft 365) or you won't get current patches for known vulnerabilities.
You need to uninstall obsolete software. Besides the security issues, there can be compatibility issues with Microsoft servers.
Outlook Support Resources
I've provided the following resources to help you learn more about using Outlook and dealing with its issues.
Using Outlook
- Basic tasks in Outlook.
- Outlook help & learning.
- A beginner’s guide for how to use Outlook email effectively.
- Microsoft Outlook quick start guide (PDF).
- How to use Outlook to be more productive.
Backup Outlook.pst
Without current backups of the Outlook.pst file, recovering your Outlook installation after a computer crash can be a nightmare.
- Export or backup email, contacts, and calendar to an Outlook .pst file.
- Back up your email in Outlook for Microsoft 365, Outlook 2019, Outlook 2016, Outlook 2013.
- Safe PST Backup Free Edition will automatically back these files up.
You can also try repairing a corrupt file.
There is more about dealing with PST files below.
Troubleshooting Outlook
- Latest updates for versions of Outlook that use Windows Installer (MSI).
- Computer Hope's Outlook Resources.
- HowTo-Outlook provides weekly tips.
- Wikipedia has information about Outlook's history and versions.
Outlook Utilities
- The OutlookAddressBookView displays the details of all recipients stored in the address books of Microsoft Outlook.
- Aid4Mail (from US$19.95) can migrate, archive and analyze the messages in all your email programs. It does this without modifying the original messages.
Moving To/From Outlook
- Import and export Outlook email, contacts, and calendar.
- Import email, contacts, and calendar from an Outlook .pst file.
- Export your email content from Outlook on Windows (Columbia University).
- Import email account data from Outlook on Macintosh (Columbia University).
- Move Outlook content to Google Workspace.
You may need to use a third-party import/export solution.
Dealing with "winmail.dat" Attachments
If you receive a message with an attached file called winmail.dat you probably will be unable to open it.
Invisible to Outlook Users
The winmail.dat is invisible to users of Outlook. Such users may not know what you are referring to when you mention it to them.
Other email clients, like Thunderbird, The Bat!, or webmail programs can all send enhanced HTML-based email without any problems for the recipient. This issue is specific to Microsoft's email clients.
Microsoft Documentation
Transport-Neutral Encapsulation Format (TNEF) gives a fuller explanation of this issue and the solution.
Other Explanations
- MozillaZine discusses TNEF for Thunderbird and other Mozilla email programs and provides some solutions.
- Wikipedia's explanation of TNEF.
Gmail Issues
OAuth 2.0
Gmail now requires OAuth 2.0 sign-in which will affect all email software.
Thunderbird and The Bat! both support OAuth 2.0 authentication for Gmail accounts but you need to turn it on in your Gmail account settings (both the incoming and outgoing server).
Important Changes to OAuth with Gmail
Starting with October 3, 2022 Google will block all third-party applications which are using the OAuth out-of-band (OOB) flow, including The Bat! prior to version 10.2. Learn more….
Thunderbird 91.8.0, released 5th April 2022, converts the authentication method of Gmail accounts to OAuth 2.0 to help users comply with Google's requirement of OAuth 2.0 for Gmail logins. These changes are required by Google.
— Mozilla Support
However, changing the account settings is only the beginning.
You then need to give Google permission to allow your email software to access your Gmail account. Check your email program's support and forums for information specific to using Gmail and OAuth 2.0.
See the following for information on making the necessary changes:
- Automatic conversion of Google mail accounts to OAuth 2.0 authentication provides help for Thunderbird.
- Using OAuth2 with Thunderbird and Gmail.
- Set up Gmail with a third-party email client provides support for Microsoft Outlook and Apple Mail.
Gmail Labels
Gmail is now configured to use labels rather than physical mailboxes to sort your email. These should be configurable when using IMAP (Gmail is designed for IMAP).
Be sure to configure your Gmail IMAP settings in your email program to match the labels you've used in Gmail. You'll need to log into your Gmail account in a browser during the process of matching labels to your email program's IMAP mailboxes.
“All mail” includes the inbox label by default. Be careful when removing this. Non-existent labels may cause retrieval issues.
- Switch to labels from folders — Google Workspace Learning Center.
- Gmail Labels: everything you need to know.
Subscription Lists Broken
Gmail made changes that broke how subscription lists were dealt with. This created problems for people subscribed to lists.
What Happened?
Gmail changed how email subscriptions were sorted. The Primary category was designed so you could quickly find your most important emails easier.
Mail deemed less-important was moved into either the Social (Facebook notifications, etc.) or Promotions (bulk mail such as ads but also subscriptions, updates and more) categories.
Unfortunately, subscription lists and update notices were categorized as Promotions, along with “junk” ads.
How to Fix It
- Click on the Promotions tab and select messages you wish to go into your primary mailbox.
- Drag the selected message onto the Primary tab.
- A pop-up message will ask if you wish to do this for all future messages from the addressee of the dragged message. Say “Yes.”
- Continue to monitor the Promotions inbox to ensure that other messages aren't getting left behind.
Alternatively, you can turn off the new tabs completely by going to the settings, click on the Inbox tab and deselect the tabs you don't want to use (e.g., Promotions) then save the changes.
Gmail Spam and Email Programs
Gmail has a very effective spam filtering system — sometimes too efficient. To compound this issue, third-party email clients like Thunderbird and The Bat! are not permitted to download mail from Gmail's Spam folder.
To resolve this issue, you'll need to log into your Gmail account using your browser.
Go to the Spam folder then select all your legitimate email messages and click on Not Spam to train Gmail's spam filters to accept mail from these addresses.
You may need to continue to check the Spam folder over time so that Gmail improves its recognition of legitimate emails rather than labelling them as spam in the future.
- How to clean up your Gmail inbox with this mass delete trick.
- Gmail marks legitimate emails as SPAM! How to correct this?
Mac Mail Issues
These resources may help you to resolve Apple MacIntosh:
- Mac Mail App Support — Apple's support for the built-in Mail app that came with your Mac.
- If you can't send or receive email on your Mac.
- Import email account data from Outlook on Macintosh.