Sourface

Thank you @lodiabai Your suggestion got me to try new things. I eventually got the NAS540 to work with the gmail smtp server. I then tried it on the NSA320 and it worked also. Now it must be down to an incompatibility on the smtp server I was originally using.

Here is a screenshot. All the information on the NSA320 is the same as on the NAS520 which works. I tried to use the gmail smtp server but that failed on the NAS520 with a different error. So, I didn't try it on the NSA320.

Your NSA221 is even older than my NSA320. They are both End of Life and not actively supported by ZyXel. I've never used their setup utility. I've always just logged in and configured from scratch. Did the person who gave it to you tell you the username and password for the device. I ask because you are usually required to…

Thank you @Zyxel_Panda I assume from your user name that this is an authoritative answer even though it was your first comment on this forum.