diff --git a/addons/mail/mail_mail.py b/addons/mail/mail_mail.py
index f984f8f3482..0bd15374ee2 100644
--- a/addons/mail/mail_mail.py
+++ b/addons/mail/mail_mail.py
@@ -240,13 +240,17 @@ class mail_mail(osv.Model):
             :return: True
         """
         ir_mail_server = self.pool.get('ir.mail_server')
+        ir_attachment = self.pool['ir.attachment']
                 
         for mail in self.browse(cr, SUPERUSER_ID, ids, context=context):
             try:
-                # handle attachments
-                attachments = []
-                for attach in mail.attachment_ids:
-                    attachments.append((attach.datas_fname, base64.b64decode(attach.datas)))
+                # load attachment binary data with a separate read(), as prefetching all
+                # `datas` (binary field) could bloat the browse cache, triggerring
+                # soft/hard mem limits with temporary data.
+                attachment_ids = [a.id for a in mail.attachment_ids]
+                attachments = ((a['datas_fname'], base64.b64decode(a['datas']))
+                                 for a in ir_attachment.read(cr, uid, attachment_ids,
+                                                             ['datas_fname', 'datas']))
                 # specific behavior to customize the send email for notified partners
                 email_list = []
                 if mail.email_to:
@@ -295,10 +299,14 @@ class mail_mail(osv.Model):
                 # /!\ can't use mail.state here, as mail.refresh() will cause an error
                 # see revid:odo@openerp.com-20120622152536-42b2s28lvdv3odyr in 6.1
                 if mail_sent:
+                    _logger.info('Mail with ID %r and Message-Id %r successfully sent', mail.id, mail.message_id)
                     self._postprocess_sent_message(cr, uid, mail, context=context)
             except MemoryError:
                 # prevent catching transient MemoryErrors, bubble up to notify user or abort cron job
                 # instead of marking the mail as failed
+                _logger.exception('MemoryError while processing mail with ID %r and Msg-Id %r. '\
+                                      'Consider raising the --limit-memory-hard startup option',
+                                  mail.id, mail.message_id)
                 raise
             except Exception as e:
                 _logger.exception('failed sending mail.mail %s', mail.id)