So, this latest error message happened while connected to the Internet
via Verizon? As explained here:
http://www.verizon.net/central/vzc.portal?_nfpb=true&_pageLabel=vzc_help_contentDisplay&objId=44427
Verizon recently began blocking port 25 connections to other (non-Verizon)
servers. Compared to the rest of the industry, they were very tardy in that
regard.
Port 587 or other non-25 ports won't work with mail.alteksystemsinc.com
because that server doesn't support them.
The following workaround should be successful when sending from home:
1. In Windows Mail go to Tools, Accounts, select your Altek mail account,
click Properties, Servers. Change the name of the outgoing (SMTP)
server to outgoing.verizon.net. Do not change the incoming server. Also,
make sure that the "My server requires authentication" option is checked.
Click the adjacent "Settings" button. Select "Log on using"
then enter your Verizon username and the associated password. Click OK.
2. Go to the Advanced tab and verify that the port number for the
outgoing (SMTP) server is still 587. Click OK. Try sending.
This setup may also work from your other home which has Comcast.