550,SMTP server error

[Sufiyan Shaikh]

Hello,

I have 4 support department created and 4 users are attached to each.
I am only able to send email from matching email and others like sales, abuse, billing, general are giving 550,SMTP server error.
I am attaching error below. 3 errors are getting logs in Activity log every time trying to open 1 ticket and send email to client.

 

Email Sending Failed - Email Sending Failed: The following From address failed: sales@example.com : MAIL FROM command failed,Account support@example.com can not send emails from sales@example.com. ,550,SMTP server error: MAIL FROM command failed Detail: Account support@example.com can not send emails from sales@example.com. SMTP code: 550 (Subject: [Ticket ID: 431648] f3qwefw3)

Email Sending Failed - Email Sending Failed: The following From address failed: sales@example.com : MAIL FROM command failed,Account support@example.com can not send emails from sales@example.com. ,550,SMTP server error: MAIL FROM command failed Detail: Account support@example.com can not send emails from sales@example.com. SMTP code: 550 (Subject: [Ticket ID: 431648] f3qwefw3)

    
Admin Email Message Sending Failed - Email Sending Failed: The following From address failed: sales@example.com : MAIL FROM command failed,Account support@example.com can not send emails from sales@example.com. ,550,SMTP server error: MAIL FROM command failed Detail: Account support@example.com can not send emails from sales@example.com. SMTP code: 550 (Subject: [Ticket ID: {$ticket_tid}] {$ticket_subject})

 

Any solution to this issue?

[WHMCS Stephen]

Hello @Sufiyan Shaikh

From the error you have provided, it appears that your SMTP system is refusing to send mail from an alternative address to the one configured within the mail configuration.

For instance, due to your error, support departments will attempt to send emails, whereas you may have configured smtp@ within your primary mail settings.

In this scenario, you would need to work with your system administrator to enable this feature within the SMTP configuration within your hosting environment.

I hope this information helps.

Regards, 

Stephen.

[Sufiyan Shaikh]

On 10/23/2025 at 1:40 AM, WHMCS Stephen said:

Hello @Sufiyan Shaikh

From the error you have provided, it appears that your SMTP system is refusing to send mail from an alternative address to the one configured within the mail configuration.

For instance, due to your error, support departments will attempt to send emails, whereas you may have configured smtp@ within your primary mail settings.

In this scenario, you would need to work with your system administrator to enable this feature within the SMTP configuration within your hosting environment.

I hope this information helps.

Regards, 

Stephen.

Thank you for your reply @WHMCS Stephen

I was able to fix this issue

[Patel H.]

On 10/23/2025 at 1:40 AM, WHMCS Stephen said:

Hello

From the error you have provided, it appears that your SMTP system is refusing to send mail from an alternative address to the one configured within the mail configuration.

For instance, due to your error, support departments will attempt to send emails, whereas you may have configured smtp@ within your primary mail settings.

In this scenario, you would need to work with your system administrator to enable this feature within the SMTP configuration within your hosting environment.

I hope this information helps.

Regards, 

Stephen.

Major email service providers do not allow this aliasing.  
That is, they do not allow an email to be sent from an ID that is not logged in with SMTP. 

to be able to send an email the sender must have the SMTP login of ID in question. 


How do you configure SMTP for department email ID's

[joeroot6543]

On 10/22/2025 at 11:50 PM, Sufiyan Shaikh said:

Hello,

I have 4 support department created and 4 users are attached to each.
I am only able to send email from matching email and others like sales, abuse, billing, general are giving 550,SMTP server error.
I am attaching error below. 3 errors are getting logs in Activity log every time trying to open 1 ticket and send email to client.

 

Email Sending Failed - Email Sending Failed: The following From address failed: sales@example.com : MAIL FROM command failed,Account support@example.com can not send emails from sales@example.com. ,550,SMTP server error: MAIL FROM command failed Detail: Account support@example.com can not send emails from sales@example.com. SMTP code: 550 (Subject: [Ticket ID: 431648] f3qwefw3)

Email Sending Failed - Email Sending Failed: The following From address failed: sales@example.com : MAIL FROM command failed,Account support@example.com can not send emails from sales@example.com. ,550,SMTP server error: MAIL FROM command failed Detail: Account support@example.com can not send emails from sales@example.com. SMTP code: 550 (Subject: [Ticket ID: 431648] f3qwefw3)

    
Admin Email Message Sending Failed - Email Sending Failed: The following From address failed: sales@example.com : MAIL FROM command failed,Account support@example.com can not send emails from sales@example.com. ,550,SMTP server error: MAIL FROM command failed Detail: Account support@example.com can not send emails from sales@example.com. SMTP code: 550 (Subject: [Ticket ID: {$ticket_tid}] {$ticket_subject})

 

Any solution to this issue?

I also have the same question because this looks like it could be related to how the different support department email addresses are authenticated or associated with the SMTP account. It seems that the support address can send successfully because it matches the SMTP account, while addresses such as sales, billing, abuse, and general are being rejected when the system tries to use them in the `MAIL FROM` command. The 550 message specifically mentioning that `support@example.com` cannot send emails from `sales@example.com` makes me wonder whether each department address needs to be configured separately or whether the SMTP server needs to explicitly authorize those sender addresses.

I’d also be interested in knowing the recommended setup when multiple departments and users need to send replies from their own department addresses. If all four addresses are supposed to use the same SMTP account, there may be a sender-alias, mailbox, or permission setting that needs to be configured on the mail server. Since the same error is appearing repeatedly in the activity log, it seems like the application is attempting to send the message correctly but the SMTP server is rejecting the sender identity. Hopefully someone who has configured multiple support departments with separate From addresses can clarify what needs to be changed.