Hello, First, best wishes to all for the new year. I manage a koha system that supports 7 volunteer-run libraries in Sheffield, UK. Since 2018 we have used gmail as a relay for sending overdue notifications etc. Recently, Google informed me that they have disabled the service due to violation of their terms of service. We are not sure exactly what they are unhappy about but we suspect it might be due to a high proportion of bounced messages, (We have rather too many incorrect email addresses in koha.) I would be interested to hear from anyone who has had a similar problem, and has found a solution. In particular, I would like some guidance on setting up Postfix to send out email directly (without using gmail as a relay), and setting up SPF, DKIM and DMARC. In case it is relevant, we are using koha 22.11. Thanks and Best Regards, Chris Brown