Any third party tools for messaging architecture/infrastructure which can be used for existing applications?

Question

Hi, We are looking to add messaging infrastructure support to our existing applications. Something like emailing through existing mail clients like exchange,outlook,lotus notes,SMTP etc. , manage address books with integration with LDAP, send mobile texts (SMS) (maybe via email to sms gateways), send secured emails to users.

Any one knows any tools or frameworks which I can look at? (paid / open source)

Thanks in advance, Aseem Chiplonkar