I have a few clients that run exchange and are getting killed in the cost per month that Exchange hosting providers charge.

I was looking at some alternatives such as Postpath and Smartermail. Does anybody have any experiences with either of these pieces of software? They need an 'Exchange Compatible' server because they use the Global Address Book, Personal Folders, and Calender functions in Outlook. Are there any other good Exchange replacements on the market?

Zimbra is another one.

Zimbra is another one.

I dont think Zimbra is a drop in replacement for Exchange.

In my personally havent found any good replacements that are truly worth the cost difference.

I have a few clients that run exchange and are getting killed in the cost per month that Exchange hosting providers charge.

I was looking at some alternatives such as Postpath and Smartermail. Does anybody have any experiences with either of these pieces of software? They need an 'Exchange Compatible' server because they use the Global Address Book, Personal Folders, and Calender functions in Outlook. Are there any other good Exchange replacements on the market?

Gordano also offer an alternative.

Check this link http://www.thewybles.com/~charles/oser/

Smartermail is good.

You can very well go for SmarterMail server which is good as Exchange servers and has good features like-

# Advanced Collaboration (Groupware) - Shared calendars, contacts, tasks, and notes
# LDAP Support
# Global Address List (GAL)
# Message Prioritization and Throttling
# Active Directory Authentication
# System-wide Email Archiving
# Over-the-Air synchronization for BlackBerry, iPhone, and Windows Mobile devices
# SmarterMail Sync for Microsoft Outlook
# SmarterMail Sync for SmartPhones and Windows Mobile devices
# Custom and Emailed reports

Spam filtering software like Declude works well in SmarterMail servers.

Thanks,
Arun

Have a look at Kerio Mailserver (http://www.kerio.com/kms_home.html).

There's a fully functional 30 day trial available for download and it's as close to a drop in Exchange replacement that we've found. It has it's pros and cons, but overall it's a really nice piece of software to work with.

ambigiousop,

Are you looking for a Windows or Linux based solution? Or both?