This article provides information about the error message given when trying to send email from SyncBack.

The error message contains a WinSock error code (in hexadecimal) at the end of the complete error message, for example:
Unable to send email: Error with connecting server;current server:;getaddrinfo failed for 25, error: 0x00002af9

The common error codes are:
  • 0x00002af9 - This is a "Host not found" error message (WSAHOST_NOT_FOUND). This means the hostname you've entered for the SMTP email server is not valid (more accurately, the resolution service your system uses is returning the message that it cannot resolve the hostname to an IP address). If you've used an actual IP address directly, then the IP address is invalid.
  • 0x0000274d - This is a "Connection refused" error message (WSACONNREFUSED). This means the hostname or IP address is valid but the server is not allowing the connection or the server cannot be contacted. The possible reasons are: the server is down/offline, the port number is incorrect (the server is not listening on that port), or a firewall is blocking the connection. For SMTP the port number should be 25 or 465 if using secure SMTP.
  • 0x0000274c - This is a "Timeout" error (WSAETIMEDOUT). This means a connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond. It generally suggests firewall or network issues.For example, a firewall may be permitting some commands/responses but blocking others.