Custom app registration - Microsoft 365
Custom app registration in Microsoft 365 / Entra admin center to avoid repeated lost credentials or reauthetication
Why use custom application registration? By default, the application uses delegated authentication using OAuth to authenticate the user to Microsoft (sometimes called modern authentication). This sometimes can pose issues if you end up running the ...
Frequent re-authentication: requiring credentials to be entered again (popup window) or app is losing credentials
If you encounter an error such as the below... AADSTS70043: The refresh token has expired or is invalid due to sign-in frequency checks by conditional access. The token was issued on 2025-10-13T12:59:49.3759371Z and the maximum allowed lifetime for ...
Microsoft Authentication - Login Loop
We have seen some reports where certain browser configuration or OS configurations or Office 365 configurations results in a login loop wherein you enter your username and password in the browser but you are taken back to the login screen. This isn't ...
Troubleshoot connection: Failed to login CONNECT_ERROR with "The remote certificate is invalid" error
Error dialog commonly shown Mitigations Try disabling any and all antivirus locally on the machine. Make sure email scanning or monitoring is turned off specifically in antivirus software (it's usually a hidden setting). Even if the main antivirus is ...
Having trouble connecting, connection failed or authentication/login failed?
First, make sure your connection settings are correct. More information about different connection settings can be found here on our help webpage (https://gearmage.com/maildownloader_howto.html#settings). If you are using Gmail, you may be asked to ...
Connections fail with error similar to 'Too many simultaneous connections'
If you have a lot of devices or clients connecting to the same email account, the mail servers may only allow certain limit of connections at a given point in time. To speed up downloads, Mail Attachment Downloader establishes multiple connections ...
Yahoo Mail IMAP connectivity problems or issues
If you are trying to connect to Yahoo, the program needs a few settings changes to work. This is because while Yahoo has allowed certain popular email programs access, they are still working on providing OAuth enabled programs access to their mail ...
Troubleshoot connection: Cannot login using modern authentication - access denied or Sign in with Google temporarily disabled for this app
Build 1067+ (same version v3.2) should fix common google authentication issues. So please upgrade first (https://gearmage.zohodesk.com/portal/en/kb/articles/latest-pro-client-and-pro-server-builds-how-to-get-them). For Microsoft and Google ...
Troubleshoot connection: Issues with login or authentication (Microsoft or Google)? Try this.
We fully support modern authentication (OAuth) with both Microsoft (Office365 Exchange, Outlook IMAP) and Google (IMAP) based accounts. The latest build fixes common auth issues: ...
Troubleshoot connection: The Autodiscover service couldn't be located or Office365/Exchange connection issues
If you see this error when trying to connect to Exchange, it likely means that either the username/password combination is incorrect or the EWS service could not be discovered. If you've already verified the username/password are correct, then ...
Troubleshoot connection: Office365/Exchange connection failed login, username/password incorrect or Autodiscover service couldn't be located.
If you are connecting to Office365, then first ensure that you are using the correct settings and are not using IMAP to connect. Latest build (new build but same version v3.2): Make sure you are on the latest build as it often contains fixes for ...
Troubleshoot connection: Exchange Office365 Auth - Custom client authentication configuration
By default, Mail Attachment Downloader uses a public client ID and delegated authentication to authenticate with Microsoft's Office 365. If you are having login issues, we would first recommend troubleshooting using the following articles: Login ...
Troubleshoot connection: Office365 or Outlook permissions
Access to Office365 or Outlook.com requires the use of Exchange Web Services (or EWS). This is the service that Mail Attachment Downloader connects to. The program uses secure modern authentication (OAuth 2) to connect to Microsoft servers. Once ...