<flow...>
        ....
        <objectstore:retrieve config-ref="ObjectStore__Configuration" key="emailSentFlag" defaultValue-ref="false" targetProperty="flowVars.emailSentFlag" doc:name="retrieve emailSentFlag"/>
        <choice doc:name="IsEmailSent?">
            <when expression="#[flowVars.emailSentFlag == true]">
                <logger level="INFO" doc:name="Log Email Already Sent"/>
            </when>
            <otherwise>
                <smtp:outbound-endpoint host="" user="" password="" to="" from="" subject="test" cc="" bcc="" replyTo="" responseTimeout="10000" ref="Gmail" doc:name="SMTP" connector-ref="Gmail"/>
                <objectstore:store config-ref="ObjectStore__Configuration" key="emailSentFlag" value-ref="#[true]" doc:name="store emailSentFlag"/>
            </otherwise>
        </choice>
    </flow>