public void setEmailSubjectByLink(String emailSubjectByLink) {
        this.emailSubjectByLink = emailSubjectByLink;
    }
<p>
The subject line for the email message template for sending a confirmation link to the user. You can set an
<code>EmailSubjectByLink</code> template only if the value of <a href=
"https://docs.aws.amazon.com/cognito-user-identity-pools/latest/APIReference/API_EmailConfigurationType.html#CognitoUserPools-Type-EmailConfigurationType-EmailSendingAccount"
> EmailSendingAccount</a> is <code>DEVELOPER</code>. When your <a href=
"https://docs.aws.amazon.com/cognito-user-identity-pools/latest/APIReference/API_EmailConfigurationType.html#CognitoUserPools-Type-EmailConfigurationType-EmailSendingAccount"
>EmailSendingAccount</a> is <code>DEVELOPER</code>, your user pool sends email messages with your own Amazon SES
configuration.
</p>

@param emailSubjectByLink
       The subject line for the email message template for sending a confirmation link to the user. You can set
       an <code>EmailSubjectByLink</code> template only if the value of <a href=
       "https://docs.aws.amazon.com/cognito-user-identity-pools/latest/APIReference/API_EmailConfigurationType.html#CognitoUserPools-Type-EmailConfigurationType-EmailSendingAccount"
       > EmailSendingAccount</a> is <code>DEVELOPER</code>. When your <a href=
       "https://docs.aws.amazon.com/cognito-user-identity-pools/latest/APIReference/API_EmailConfigurationType.html#CognitoUserPools-Type-EmailConfigurationType-EmailSendingAccount"
       >EmailSendingAccount</a> is <code>DEVELOPER</code>, your user pool sends email messages with your own
       Amazon SES configuration.
aws-java-sdk-cognitoidp/src/main/java/com/amazonaws/services/cognitoidp/model/VerificationMessageTemplateType.java