When you connect a mailbox with Connect IMAP/SMTP, IntelliDesk must sign in to two servers: IMAP (incoming mail) and SMTP (sending your replies). Test connection tries both and shows OK or Error for each, with the server's error message underneath. Connect account only becomes available once both show OK.
This article covers the usual reasons a test fails. For Outlook, Hotmail and Microsoft 365, don't use IMAP at all: use Connect Outlook / Office 365 instead.
The password is wrong, or it needs an app password
This is by far the most common cause. The error usually mentions authentication, login or credentials.
Many providers don't accept your normal password from other apps once two-step sign-in is on. They want an app password: a separate password you create in the account's security settings. Pick your provider in Email provider and IntelliDesk shows where to create one:
- Gmail / Google Workspace: Google Account → Security → 2-Step Verification → App passwords. (Or use Connect Gmail instead, which needs no password.)
- Yahoo: Account security → Generate app password.
- iCloud Mail: create an app-specific password at appleid.apple.com.
- Zoho Mail: turn on IMAP access in Zoho Mail's settings, and use an app-specific password if you have two-factor sign-in.
Paste the app password into Password / App password, with no spaces before or after it.
The username is wrong
IntelliDesk signs in with the Email address you enter, so enter the full address of the mailbox (for example support@yourcompany.com). If your mail server expects a different login, such as a shared mailbox on Exchange or a hosted server where the login is support or DOMAIN\support, put that in Username (only if different from the email address). IntelliDesk then uses it for both IMAP and SMTP, and still sends from the email address. Leave it empty otherwise.
The server name is wrong
If the error starts with Could not resolve host or Host does not resolve, the server name doesn't exist. Check the spelling of the Host for IMAP and SMTP.
For email that comes with your website hosting, pick Other (my web host) and use the exact settings your host gives you. They're often mail.yourdomain.com, but not always, so check your host's help pages or ask them.
Zoho accounts in Europe use imap.zoho.eu and smtp.zoho.eu rather than the .com servers.
If the error says Host resolves to a private address, the server name points to an internal network address that IntelliDesk can't reach from the internet. Use your mail server's public address.
The port isn't allowed, or doesn't match the security setting
IntelliDesk accepts these ports:
- IMAP: 993 or 143. Otherwise you'll see IMAP port … is not allowed. Use 143 or 993.
- SMTP: 465, 587 or 25. Otherwise you'll see SMTP port … is not allowed. Use 25, 465, or 587.
The port and Security setting have to go together:
| Server | Port | Security |
|---|---|---|
| IMAP | 993 | SSL/TLS |
| IMAP | 143 | STARTTLS |
| SMTP | 465 | SSL/TLS |
| SMTP | 587 | STARTTLS |
A mismatch (for example port 587 with SSL/TLS) usually shows up as a timeout or a connection error. The provider presets fill in matching values for you.
IMAP works but SMTP fails (or the other way round)
Some providers use different server names for incoming and outgoing mail, or turn off SMTP sending for some accounts. Check the SMTP host and port with your provider. Both have to pass before you can connect, because IntelliDesk sends your replies through SMTP.
The test takes a long time and then fails
IntelliDesk waits about 10 seconds for each server to answer. A timeout usually means a wrong port or security setting, or a firewall at your host blocking outside connections. Ask your host whether IMAP and SMTP access from outside apps is allowed.
After you've connected
- IntelliDesk checks IMAP mailboxes every 5 minutes. Use Sync mailbox to check straight away.
- If a check fails because the server didn't answer, the card shows Sync is retrying and tries again automatically. After 5 failed checks in a row it moves to Error and stops checking until you fix it.
- If the password changes later, the server rejects the sign-in and the card shows Error straight away. Click Edit settings, enter the new password, Test connection, then Save changes. Your tickets and sync position are kept.
- Replies sent through SMTP aren't copied into the mailbox's Sent folder. The ticket in IntelliDesk is the record of what was sent.
When to contact support
If Test connection passes but the card later goes to Error with a message you don't understand, or you've checked every setting with your provider and the test still fails, contact IntelliDesk support. Include the provider, the host and port you used, and the exact error from the test.
Related: Connecting a mailbox: Gmail, Outlook, and IMAP · Reconnecting a mailbox that shows Error