A technical hitch saw 100 advisers receive the same email from James Hay more than 1,000 times over the weekend.
A client relationship manager at the SIPP provider sent a case study on Friday morning but a malfunction caused the message to re-send continually for the rest of the day as well as through Saturday and Sunday. Some advisers were still receiving the email this morning.
Although the company attempted to recall the message once the fault had been spotted on Friday, the recall notification was also sent out hundreds of times.
Keith Churchouse, director of Churchouse Financial Planning, says he was unable to receive or send emails over the weekend as a result of the mishap.
"It's quite lucky we actually came in on Saturday so we could do something about it," he says. "There were, quite literally, hundreds of these things and my mailbox went over its limit. Some clients' emails would have bounced back."
Advisers have also complained they were not blind copied - or BCC'd - in the emails, but were visible to every recipient.
A James Hay spokesman says: "We apologise for the disruption caused to IFAs as a result of these emails.
"We are working as quickly as possible to identify what may have caused this issue, be that internal or external, and will rectify it as soon as we can."
Will assess regulation
Client was warned of risk
Megan Butler keynote speech at Women in Finance summit
Market anticipates a May hike
Newly-formed Mobius Capital Partners