Why does an old project email matter years after it was sent?
An email confirming a design decision, a material substitution, or a scope change doesn't stop mattering once the project completes. Professional indemnity liability in AEC frequently runs for a decade or more after practical completion, which means an email sent today could be the deciding piece of evidence in a dispute that hasn't happened yet.
Louise Hunt, Operations Manager at Advanced Roofing, described exactly this scenario:
With Mail Manager, we can be confident that we can find the email that will protect the company financially. If a contractor says in five years' time that we didn't do something, we can literally go back to the email now and find the proof we need.
Five years was her example. For many AEC firms, the exposure window is longer still.
How long can professional indemnity liability last on a construction project?
Liability periods vary by contract and jurisdiction, but long-tail exposure is a defining feature of AEC work. A design decision made today can still be the subject of a claim years after the building is complete and occupied, long after the project team has moved on to other work - or other firms entirely.
The correspondence that explains what was agreed, why a decision was made, and who approved it needs to survive far longer than the career of the person who wrote it. If that correspondence lives in a personal Outlook inbox, it has an effective expiry date that has nothing to do with how long the firm might actually need it.
What happens when the person who sent the email has left the firm?
This is where the risk becomes concrete. The engineer who approved a variation in 2019 may not work at the firm in 2029. Their inbox may have been archived, deleted, or made inaccessible when they left. Even where an archive exists, someone has to know it exists, request access, and search through years of email hoping to find the right thread - and most people won't get that far before giving up.
An email that was never filed to the project it relates to effectively disappears the moment its sender leaves. The information technically still exists somewhere. Practically, it's gone.
How do centrally filed emails solve the long-tail retention problem?
The alternative is to file emails to the project, not the person. When Ideagen Mail Manager files an email at the point of sending, it becomes part of the project record permanently, independent of who sent it, who received it, or whether they still work at the firm. The email is retrievable by anyone who needs it, for as long as the project record needs to exist - which, given AEC liability periods, is considerably longer than most people's tenure at a single firm.
This is what separates a firm that can defend a decade-old decision from one that's relying on the hope that someone, somewhere, kept a copy.
Ideagen Mail Manager supports over 50,000 users across 2,500+ firms worldwide.
See how Mail Manager files project emails as they're sent
Frequently asked questions
How long should an AEC firm keep project emails?
Long enough to cover the professional indemnity liability period relevant to the project, which can extend a decade or more after completion. Because that window is long, the safest approach is to retain project correspondence indefinitely rather than applying a short deletion policy.
What happens to an email if the sender leaves the firm?
If the email was never filed to a central project record, it typically becomes inaccessible - trapped in an archived or deleted personal inbox that someone would need to know exists and request access to before they could even begin searching it.
Why can't firms just archive departing employees' mailboxes?
Archived mailboxes preserve the data but not practical access. Someone has to know the archive exists, get permission, and search through years of email hoping to find the right thread - most people won't get that far.
How does filing emails to a project rather than a person solve this?
When an email is filed to a project at the point of sending, it becomes part of that project's permanent record, independent of who sent or received it. It stays findable regardless of staff turnover.
Does this only matter for large firms?
No. Any AEC firm taking on liability for design or construction decisions faces the same long-tail exposure, regardless of size. Advanced Roofing, a UK roofing and cladding contractor, is a direct example of a smaller firm managing exactly this risk.