Thank you for posting your query in the Community. If you are using the default/stock mail app then you don't have to manually enter the SMTP server address; you can follow the instructions listed below;
Open the iOS Settings app.
Tap Accounts & Passwords
Tap Add Account.
Enter your full Rogers email address and tap Next.
Enter your email account password and tap Sign in.
If you must enter the SMTP address;
Outgoing Server: smtp.broadband.rogers.com or smtp.nl.rogers.com
Outgoing Port: 465
SMTP AuthenticationEmail address: Enter your full Rogers Yahoo! email address Username: Enter your full Rogers Yahoo! email address