Do I need to change the php. ini file after using PHPMailer?-php Tutorial

After PHPMailer is used, do I need to change the php. ini file? I can use the tutorial on the Internet to send an email directly. I don't need to change the IIS or PHP. ini file. But here I will report an error:
Warning: mail (): Failed to connect to mailserver at "localhost" port 25, verify your "SMTP" and "smtp_port" setting in php. ini or use ini_set () in C: \ inetpub \ wwwroot \ test \ conn \ pwdEmail. php on line 43 Mail Sent. SMTP-> ERROR: Failed to connect to server: (0)
SMTP Error: cocould not connect to SMTP host. An Error occurred while sending the email: SMTP Error: cocould not connect to SMTP host.
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How did you use it? How can I use the mail () function?
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Forgot to block it. thank you for your advice!

How did you use it? How can I use the mail () function?
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Could you tell me another small question: I tried the smtp method of 163, and the connection could not be reached! I tried my QQ mailbox again. I can connect it, but it was filtered out before it was sent !!!! You must enter the verification code on the login page of the QQ mailbox to complete sending!
Thank you for your guidance!