Invalid certificate

[elzbelz]

Hi

Could anyone help me please

I cant send emails and it just says invalid certificate. 

It's been since mid July

Thanks

[-Robot-]

You will need to provide more information for us to try and assist you?

What application you using? Samsung mail, Outlook, etc....

What platform are you using? Outlook.Com, gmail.com, exchange, office 365? Etc.....

Are you having issue when on WiFi, using data or both?