No maximums.  Here's a who on emelie our mail file server:

 34:        ndb    il!135.104.9.11!14850      0      0 (1,3) (-615121,3124,-6876) (55,255,168,0)
 31:        rsc     il!135.104.9.23!6435      0      0 (1,3) (-2444,8056,-1944) (5886,288,144,0)
 28:       none    il!135.104.9.29!28508      0      0 (1,3) (-1049,5752,-1236) (2874,235,117,0)
 27:       none    il!135.104.9.55!10848      0      0 (1,3) (-3294,4108,-3468) (3208,203,98,0)
 26:       none   il!135.104.9.129!11273      0      0 (1,3) (-1603,6400,-1848) (8959,365,200,0)
 25:       none     il!135.104.9.2!28284      0      0 (1,3) (-17593,1252,-8748) (406,547,214,0)
 24:        jmk     il!135.104.9.16!6208      0      0 (1,3) (163,1384,-84) (3170,414,192,0)
 23:     mjcoss   il!135.104.52.12!11579      0      0 (1,3) (-3852140,232,-9768) (2037,179,76,0)
 22:        rsc     il!135.104.9.16!6209      0      0 (1,3) (-1094118602,8044,-1956) (800,400,200,0)
 21:        ehg    il!135.104.9.69!27142      0      0 (1,3) (-4887,1936,-5088) (1814,258,138,0)
 20:       none     il!135.104.9.2!28283      0      0 (1,3) (-1012,3364,-1260) (3202,481,177,0)
 19:       sape    il!135.104.9.67!16524      0      0 (1,3) (-24589544,7528,-2472) (5592,283,122,0)
 18:        rsc     il!135.104.9.23!6436      0      0 (1,3) (-1452446167,1816,-8184) (721,413,212,0)
 17:        sys    il!135.104.9.15!31929      0      0 (1,3) (-536757,652,-9348) (3051,455,222,0)
 16:       none    il!135.104.9.15!31936      0      0 (1,3) (-183238,976,-9024) (2585,258,125,0)
 15:       upas    il!135.104.9.15!31923      0      0 (1,3) (-222,6196,-468) (1655,410,191,0)
 14:         pb     il!135.104.9.44!9720      0      0 (1,3) (-3890,5128,-4140) (800,400,200,0)
 13:       none     il!135.104.9.6!14336      0      0 (1,3) (-89614172,6652,-3348) (4262,423,209,0)
 12:        ynl     il!135.104.9.6!14329      0      0 (1,3) (198,5584,-12) (260,335,139,293)
 11:       none    il!135.104.9.67!16521      0      0 (1,3) (-2198,6484,-2448) (800,400,200,0)
 10:      hobby   il!135.104.52.81!14329      0      0 (1,3) (-6097,5512,-4488) (1254,537,241,0)
  9:       sape    il!135.104.9.91!19735      0      0 (1,3) (-11194,4876,-5124) (2750,273,145,0)
  8:   presotto    il!135.104.9.65!11393      0      0 (1,3) (-6661,9052,-948) (233,315,224,0)
  7:        rsc     il!135.104.9.6!14335      0      0 (1,3) (-37851961,1780,-8220) (89,416,222,0)
  6:       none    il!135.104.9.73!15374      0      0 (1,3) (-9052,8068,-1920) (458,321,193,0)
  5:        rsc    il!135.104.9.92!28844      0      0 (1,3) (-17245079,1420,-8580) (7752,236,105,0)
  4:        jmk   il!135.104.9.222!10146      0      0 (1,3) (-11102,736,-9264) (800,400,200,0)
  3:       none    il!135.104.9.92!28842      0      0 (1,3) (-7463,8500,-1500) (3625,477,236,0)
  2:        rsc   il!135.104.9.222!10147      0      0 (1,3) (-1374505802,1900,-8100) (800,400,200,0)
  1:       upas     il!135.104.9.7!11691      0      0 (1,3) (-383865,3904,-6096) (2320,274,146,0)
  0:        adm                  console      0      0

It just shows connections from other machines, not users on a system.  We're probably
at our low point for number of users.  We've only got 30 or so users logged in these
days at any one time.