I can receive but not send emails

• Start Outlook, go to 'Tools' and select 'E-mail Accounts...'

• Select 'View or change existing email accounts' and hit 'Next'
  

• Select the email account you're having sending issues with and hit 'Change'
  

• On the 'Internet E-mail Settings (POP3)' window, click on 'More Settings...'
  

• Go to the 'Outgoing Server' tab and select 'My Outgoing server (SMTP) requires authentication'

• Select 'Use same settings as my incoming mail server' - if not selected by default - and hit 'OK'

• Hit 'Next' then 'Finish' to validate the changes
  

• Launch Outlook; go to 'Tools' and select 'Account Settings...'

• Select the email account you're having sending issues with and hit 'Change'
  

• Click on 'More Settings...' and go to the 'Outgoing Server' tab
  

• Check the box 'My outgoing server (SMTP) requires authentication'

• Select 'Use same settings as my incoming mail server' - if not selected by default - then hit 'OK'

• Click on 'Next' then hit 'Finish' to validate the changes

• Start Outlook, go to the 'File' ribbon and click on 'Account Settings'

• Click on 'More Settings...' and go to the 'Outgoing Server' tab

• Check the box 'My outgoing server (SMTP) requires authentication'

• Select 'Use same settings as my incoming mail server' - if not selected by default - then hit 'OK'

• Click on 'Next' then hit 'Finish' to validate the changes.