Problems sending Emails
Most Aqilla clients send e-mails (with attachments) from Aqilla to their customers and suppliers; typical examples are:
sales invoices
sales credit notes
self billing invoices
debtor statements
purchase orders
creditor remittance advice notes
Recipient e-mail addresses are defined against customer, debtor, supplier and creditor reference records. "Sent from / Reply to" e-mail addresss are defined at Configuration > Companies.
From time-to-time you may receive a "bounceback" e-mail message. There are various easily understood reasons for this such as:
incorrect recipient e-mail address has been used
recipient mailserver is down
recipient is on vacation and has set auto reply - usually means the original e-mail made it though
Less easy to understand if you get a message like this:

The natural thing to think is that Aqilla is having a problem sending e-mails but this is almost never the case. If you ask Aqilla Support to help you solve this sort of problem we will send you to this Help page in the first instance and refer you to;
https://en.wikipedia.org/wiki/Reverse_DNS_lookup
Note this is a bit "techie"!
A simpler explanation is that Aqilla is sending e-mails on your behalf and is therefore sending e-mails from our server using multiple domains - e.g. accounts@bigco.com; finance@yourco.co.uk - and the recipient mailserver thinks that something is wrong because the IP address the e-mail is coming from (i.e. Aqilla's server) does not match the domain name the recipient mailserver expects (e.g. yourco.co.uk) - from its reverse DNS lookup etc. There is nothing Aqilla can do about that.
However all you need to do is contact whoever manages your domain (e.g. yourco.co.uk - probably your internet service provider) and ask them to add an SPF record to that domain to specify that "it's OK" that Aqilla's server is sending an e-mail on behalf of that domain. Their techies will need to know the IP addresses that Aqilla might use (to add to their "whitelist") and they are:
46.37.166.60
46.37.166.61
46.37.166.62