Unable to send email on data

[#1]

This is what I get from gmail

[#2]

Just to confirm do you get this message when connected to plusnet or to mobile data.? The message suggests your current IP Address has been blacklisted due to suspicious activity, probably by a previous user?

[#3]

If it's on mobile data , it's likely that it's using CGNAT in which case many users will be sharing the same public IP. Only takes one to be 'naughty' and the IP will be blacklisted...

[#4]

I get this when I connect with mobile data.

[#5]

I would try disconnecting the mobile data for a while to see if you get a different IP Address, they are usually not that sticky

What is my IP Address  will report your current one

[#6]

there is something that plusnet are doing just got a new domain so i can move my emails, now the new one will not work on plusnet with POP3, soon as i go to my mobile from from computer all works find. they must be block something !!  

[#7]

Plusnet does not block anything in respect of access to other provider's email services.  If anything is being blocked, the block probably comes from the third party ... assuming all of the settings are correct.

Plusnet might block access to THEIR OWN SMTP server in certain conditions to protect the integrity of the service for all users.

You have not offered much information to go on, beyond you cannot get some third party email connection working.  This board is for issues with PLUSNET's email services.  Third party issues should be raise on the general tech help board please.