Email notification configuration steps

Dear All,

Netweaver 7.4  i want to configure Email Notification in EP System.

i followed below steps but i am not getting Emails. i tried with the gmail and aol but not getting Emails.

1) http://localhost:50000/nwa/java system properties > server > java mail client

1. mail.from : xyz@aol.com
2. mail.host : aol.com
3. mail.password : xxxxxxx
4. mail.smtp.auth : false
5. mail.smtp.host : smtp.aol.com
6. mail.smtp.password :xxxxxx
7. mail.smtp.port : 25 /465 /587 (one by one using ports and restart instance)
8. mail.transport.protocol  : SMTP
9. mail.user : xyz@aol.com

   j.   sslCertificate : default

2) http://localhost:50000/nwa/Certificates and Keys

javamail > default

created default certificate as manually

countryName  : US

stateOrProvinceName : Virginia

organizationName : AOL

localityName : Dulles

organizationalUnitName : AOL Inc

commonName * : smtp.aol.com

Error at log (Invalid certificate [default-cert]! SSL connection is not possible.)

3) http://localhost:50000/useradmin

configuration > Notification Email

Host Name of the SMTP Server: smtp.aol.com

System : xxx@aol.com

Central Administrator : xxx@aol.com

Workflow : xxx@aol.com