I contacted tech support at iambic Software regarding software lock-ups with Agendus Mail [dumpingagendus, buyingagendusmail] on my Zodiac. They replied within 2 days, offering an apology and assuring me that my issue would be escalated to the engineers. Alas, that was the last I heard from them. Agendus Mail has been a total hassle from the purchase process to the usability. Rather than deal with iambic again, I've decided to ask Handango for a refund. I had a good experience with Handango support in the past, and I'm anxious to see if that continues.
I don't recommend buying Agendus Mail for PalmOS, and I would think hard before ordering software from iambic again. iambic used to sell great software for classic Palm devices, including TinySheet, which I still use to this day. But along with TinySheet, iambic has abandoned or provided terrible support for many apps that I've purchased, including FastWriter, iambic Office, iambic Mail, and now Agendus Mail.
There are many PalmOS e-mail alternatives, including the highly rated SnapperMail software. My demo version of SnapperMail was better than Agendus Mail in every respect, except that it couldn't hot sync with Outlook mail. In exchange for reliable software, I can certainly live without an Outlook sync feature.