Unable to SEND emails since switch to EE

[#1]

Going over old ground here but...yes, I can log-in and I can receive emails in webmail but cannot send them. i get one of the following error messages briefly pop-up:

1. connection error (failed to reach the server)

2. SMTP error (550): Failed to set sender

I am using the portal chat function to communicate with their techies.

I have rarely ever used roundcube in the past as it is almost always slow and often erratic. 

Sending via webmail has been possible at times over the last few days but given Greenby's general unreliability, it's hard to know what is causing these errors.

[#2]

I checked the 'test connection to server' button on the accounts page in Thunderbird and got this:

outgoing server:
Description: <not specified>
Server Type: SMTP Outgoing Server
Server Name: mail.enmail.co
Port: 465
User Name: [email protected]
Authentication method: Normal password
Connection Security: SSL/TLS
Successfully established a secure connection to mail.enmail.co:465.

[#3]

@Bookworms 

"Going over old ground here but...yes, I can log-in and I can receive emails in webmail but cannot send them. i get one of the following error messages briefly pop-up:

1. connection error (failed to reach the server)

2. SMTP error (550): Failed to set sender

I am using the portal chat function to communicate with their techies.

I have rarely ever used roundcube in the past as it is almost always slow and often erratic.

Sending via webmail has been possible at times over the last few days but given Greenby's general unreliability, it's hard to know what is causing these errors."

"1. connection error (failed to reach the server)"

That's just a temporary glitch that happens now and then. Sending usually works OK a few seconds later.

"2. SMTP error (550): Failed to set sender"

From Search Assistant:
SMTP error 550: Failed to set sender typically indicates that the email server is rejecting the message because the sender's email address is not recognized or authenticated. To resolve this, ensure that SMTP authentication is enabled in your email client settings.

Could this be some mix up between your email address and actual Plusnet username in the settings on your email client?

[#4]

I'm obviously no expert but my gut feeling is that Greenby has failed to properly set up a system that takes account of former plusnet users with changed credentials. Hence, perhaps, their chatbot advice to disable security ...

Meanwhile I await the advice from their tech advisor.