We have what seems to be a general issue with customers who are heavy users of SO mailings. I discovered this during a prep for upgrading superoffice to the latest version from 8.0. I have moved a Service installation from emarketing.company.dk to superoffice.company.dk/Service as per best practise described by Margrethe in the presentation from EW 2017. This does however not really mention anything about backward compatibility with old shipments.
Then to prevent loss of images and tracked links, i've made a 301 redirect on the IIS from the old site to redirect all traffic to the new hostname. The good news is that images and attachment links are redirected just fine, so mailings doesn't look crippled in the mail client of the end receiver. All links are dead though, including the unsubscribe links - which is a big bummer!
To demonstrate, i made a shipment before we made the change that was confirmed working, and then one after:
Link before hostname change: http://emarketing.company.dk/scripts/customer.fcgi?action=ejLink&key=12024:40050:677048:9a537a524ee441804c7383731c6f31070987f570&sai=9786225
Link after sending the same shipment after the change: http://superoffice.company.dk/Service/scripts/customer.fcgi?action=ejLink&key=12024:40050:677048:9fe4b958188c5787719ef6cf38c195b8b962eda3&sai=9786225
select * from dbo.s_shipment where id = 12024 -- ID of the Shipment
select * from dbo.s_link where id = 40050 -- Id of the link
select * from dbo.person where person_id = 677048 -- Id of the receiver
select * from dbo.?????? where id = '9a537a524ee441804c7383731c6f31070987f570' -- id of what???
12024:40050:677048: and &sai=9786225 is similar in both links, but the long hash-like string differs.
My theory is that the unique part of the link contains information about the original hostname that needs to be verified against the called link, once the receiver clicks it. When SuperOffice tries to regenerate the hash using the changed hostname URL, the hash will not end up being the same, and therefore the link is being rejected.
So what are other customers / partners doing to prevent broken links when upgrading to 8.1+ on premise?
Please ellaborate, and share a fix if you have any :)