Knowledgebase : Technical, Configuration and Devices > Email

Sending emails through Office365 sometimes causes message send failure with an error of 550 5.7.64 TenantAttribution; Relay Access Denied.

  1. In Office Admin go to Exchange
  2. In 'Mail Flow' go to  Connectors
  3. Use the wizard to complete the Connector process.

Make sure the external IP is recorded as an allowed address on the Inbound Connector in Office 365:











Also, add the IP address to the SPF record in Public DNS like this:

v=spf1 ip4:, ~all

One other possible cause of this issue is if the application, when it composes the email, uses a domain other than what is on the accepted domains list. For example, if your tenant has 3 defined domains – BobsGarage.Com, TimsGarage.Com andJohnsGarage.Com and the application sending the email uses a domain like GaragePower.Com, then the connector in Office 365 will reject the email. If you receive the relay error, here is the order I would take for troubleshooting:

  • Verify Sender address is using an accepted Domain (in the application, or message header)
  • Send the email to an internal recipient – check headers for IPs to match in the connector
  • Check your SPF record to make sure all IP addresses are listed as well


If emails are not being received by the intended recipient there are a number of items to consider.  Usually, if there is a problem with sending the email out of your mail server, you would receive quite a detailed error message which will include, somewhere in the text, the reason that the emails are not going out of your server.

Check the following:

1. Are the settings for your outgoing mail server correct.
    Use to check that your SMTP (outgoing) mail server details are correct.


Office 365 by default can only send emails from one email account (the account name).  Errors will occur if you try and send using the operator email address etc.

This may be able to be addressed by configuring Mailbox permissions.  Refer to the article below.  This should be carried out by the hardware technician or client.


NOTE: If this error occurred while trying to establish an FTP data connection, also see this:

A WSAEWOULDBLOCK error when trying to establish a TCP/IP socket connection indicates one of the following conditions:

  1. A firewall at either the client or server side is blocking the connection.
  2. There is no server listening at the remote host:port to accept the connection
  3. Some other software, such as an anti-virus or anti-spyware program is blocking the connection.
  4. The server was too slow in accepting the connection.  Increase the value of the ConnectTimeout property.

You may open a DOS prompt and try to telnet to the remote host:port to test connectivity. This page provides more information: WSAEWOULDBLOCK

Note: It is impossible for the client to distinguish between any of the cases described above.  It’s similar to if you were knocking on a door and nobody answers — you have no information — you don’t know if the person simply chose not to answer the door, if the person is not home, or if the person simply cannot hear the knocking.  In all cases, the client’s knowledge is the same: there is no response and you have to decide how long you’re willing to wait…

If you getting some of your emails rejected as spam and you are using an Office365 account as your SMTP (outgoing) email server, you must use SMTP Encryption and include your login credentials in the Account Authentication section in Setup > Providers > Email 

Otherwise some POP or IMAP (incoming) email servers might reject an email as spam. 

It is likely that you will require your IT provider to assist you to get the correct information for the Office365 account login and password.

The following link provides further information.

Setting up Gmail as an SMTP account for a Provider


To setup Email for a Provider using a Gmail account, go into;

-Setup   -Provider   -Email    (as below).


When you try to Test Connection it will fail and the Gmail account will receive a Security alert.


You will need to get the client to login to the Gmail account to do the next steps.

  1. There will be a security alert email in the inbox.

2.   Click on “Yes it was me” and you will go to the Less secure app blocked Click on “Learn more”

3.    From the Less secure apps page, click on “Less secure app access” link.

4.   Change the setting to ON.

5.    If you retry Test Connection, it should now allow emails through.

  • With upcoming security changes by Google, new application connections will not be able to be made after July 2020.
  • Existing connections will stop after Feb 2021.

If the Test Email or Test Connection functions are not working or emails can't be sent and an error appears "ActiveX component not creating instance of object", it is possible that the Chilkat files are not correctly installed or registered.

Using RegisterBatch.exe may not help.

Use ChilkatSetup.exe (which is in the \spmwin directory) to install the necessary files and register them.

Make sure the virus checker and UAC are turned off first and you are using a login with Administrator rights

Go to this site and use the SMTP test option.  It has a very good set of diagnostic tools.

It will report information regarding the connection and transaction time.

The MX  test is also good for diagnosing email problems.