SERVFAIL and lame server errors for google MX servers

[andys]

Hi, 

  I am seeing SERVFAIL errors from our FreeBSD BIND 9.5.0.2 server when 
looking up MX records for google.com.
We have a customer complaining they are having mail delivery errors as a 
result which have a serious impact to this customer, so I need to know if 
its a problem with our server. 

So far the symptoms have been that in the past couple of weeks we have seen 
errors like: 

> Default Server:  ns1.ukgrid.net 
> 
> Address:  85.159.60.194 
> 
>   
> 
>> set type=mx
> 
>> googlemail.com
> 
> Server:  ns1.ukgrid.net 
> 
> Address:  85.159.60.194 
> 
>   
> 
> *** ns1.ukgrid.net can't find googlemail.com: Server failed

then a few moments later if you try again the query succeeds. 

Now on the face of it this looks like a problem with google DNS to me (but 
Im no BIND expert), but the thing that worries me is that restarting named 
on our server seems to completely clear the problem, at least for some days.
I have also tried upgrading BIND, we were previously running on the FreeBSD 
ports version 9.5.0.1 and now on 9.5.0.2 but the same issue is still being 
seen. 

Any advise on whether we have an issue or its just a problem with google 
servers would be appreciated. 

thanks in advance, Andy. 

PS currently Im not seeing the problem so it makes trouble shooting very 
hard!